[PATCH v7 0/2] json-writer V7

[PATCH v7 0/2] json-writer V7

[git]

From: Jeff Hostetler <jeffhost@microsoft.com>

Here is V7 of my json-writer patches.  Please replace the existing V5/V6
version of jh/json-writer branch with this one.

This version cleans up the die()-vs-BUG() issue that Duy mentioned recently.
It also fixes a formatting bug when composing empty sub-objects/-arrays.

It also includes a new Python-based test to consume the generated JSON.

I plan to use the json-writer routines in a followup telemetry patch series.

Jeff Hostetler (2):
  json_writer: new routines to create data in JSON format
  json-writer: t0019: add Python unit test

 Makefile                    |   2 +
 json-writer.c               | 419 ++++++++++++++++++++++++++++++++
 json-writer.h               | 113 +++++++++
 t/helper/test-json-writer.c | 572 ++++++++++++++++++++++++++++++++++++++++++++
 t/t0019-json-writer.sh      | 274 +++++++++++++++++++++
 t/t0019/parse_json_1.py     |  35 +++
 6 files changed, 1415 insertions(+)
 create mode 100644 json-writer.c
 create mode 100644 json-writer.h
 create mode 100644 t/helper/test-json-writer.c
 create mode 100755 t/t0019-json-writer.sh
 create mode 100644 t/t0019/parse_json_1.py

-- 
2.9.3

[PATCH v7 1/2] json_writer: new routines to create data in JSON format

[git]

From: Jeff Hostetler <jeffhost@microsoft.com>

Add a series of jw_ routines and "struct json_writer" structure to compose
JSON data.  The resulting string data can then be output by commands wanting
to support a JSON output format.

The json-writer routines can be used to generate structured data in a
JSON-like format.  We say "JSON-like" because we do not enforce the Unicode
(usually UTF-8) requirement on string fields.  Internally, Git does not
necessarily have Unicode/UTF-8 data for most fields, so it is currently
unclear the best way to enforce that requirement.  For example, on Linx
pathnames can contain arbitrary 8-bit character data, so a command like
"status" would not know how to encode the reported pathnames.  We may want
to revisit this (or double encode such strings) in the future.

The initial use for the json-writer routines is for generating telemetry
data for executed Git commands.  Later, we may want to use them in other
commands, such as status.

Helped-by: René Scharfe <l.s.r@web.de>
Helped-by: Wink Saville <wink@saville.com>
Helped-by: Ramsay Jones <ramsay@ramsayjones.plus.com>
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
---
 Makefile                    |   2 +
 json-writer.c               | 419 ++++++++++++++++++++++++++++++++
 json-writer.h               | 113 +++++++++
 t/helper/test-json-writer.c | 572 ++++++++++++++++++++++++++++++++++++++++++++
 t/t0019-json-writer.sh      | 236 ++++++++++++++++++
 5 files changed, 1342 insertions(+)
 create mode 100644 json-writer.c
 create mode 100644 json-writer.h
 create mode 100644 t/helper/test-json-writer.c
 create mode 100755 t/t0019-json-writer.sh

diff --git a/Makefile b/Makefile
index a1d8775..4ae6946 100644
--- a/Makefile
+++ b/Makefile
@@ -666,6 +666,7 @@ TEST_PROGRAMS_NEED_X += test-fake-ssh
 TEST_PROGRAMS_NEED_X += test-genrandom
 TEST_PROGRAMS_NEED_X += test-hashmap
 TEST_PROGRAMS_NEED_X += test-index-version
+TEST_PROGRAMS_NEED_X += test-json-writer
 TEST_PROGRAMS_NEED_X += test-lazy-init-name-hash
 TEST_PROGRAMS_NEED_X += test-line-buffer
 TEST_PROGRAMS_NEED_X += test-match-trees
@@ -820,6 +821,7 @@ LIB_OBJS += hashmap.o
 LIB_OBJS += help.o
 LIB_OBJS += hex.o
 LIB_OBJS += ident.o
+LIB_OBJS += json-writer.o
 LIB_OBJS += kwset.o
 LIB_OBJS += levenshtein.o
 LIB_OBJS += line-log.o
diff --git a/json-writer.c b/json-writer.c
new file mode 100644
index 0000000..f35ce19
--- /dev/null
+++ b/json-writer.c
@@ -0,0 +1,419 @@
+#include "cache.h"
+#include "json-writer.h"
+
+void jw_init(struct json_writer *jw)
+{
+	strbuf_reset(&jw->json);
+	strbuf_reset(&jw->open_stack);
+	strbuf_reset(&jw->first_stack);
+	jw->pretty = 0;
+}
+
+void jw_release(struct json_writer *jw)
+{
+	strbuf_release(&jw->json);
+	strbuf_release(&jw->open_stack);
+	strbuf_release(&jw->first_stack);
+}
+
+/*
+ * Append JSON-quoted version of the given string to 'out'.
+ */
+static void append_quoted_string(struct strbuf *out, const char *in)
+{
+	unsigned char c;
+
+	strbuf_addch(out, '"');
+	while ((c = *in++) != '\0') {
+		if (c == '"')
+			strbuf_addstr(out, "\\\"");
+		else if (c == '\\')
+			strbuf_addstr(out, "\\\\");
+		else if (c == '\n')
+			strbuf_addstr(out, "\\n");
+		else if (c == '\r')
+			strbuf_addstr(out, "\\r");
+		else if (c == '\t')
+			strbuf_addstr(out, "\\t");
+		else if (c == '\f')
+			strbuf_addstr(out, "\\f");
+		else if (c == '\b')
+			strbuf_addstr(out, "\\b");
+		else if (c < 0x20)
+			strbuf_addf(out, "\\u%04x", c);
+		else
+			strbuf_addch(out, c);
+	}
+	strbuf_addch(out, '"');
+}
+
+static inline void indent_pretty(struct json_writer *jw)
+{
+	int k;
+
+	if (!jw->pretty)
+		return;
+
+	for (k = 0; k < jw->open_stack.len; k++)
+		strbuf_addstr(&jw->json, "  ");
+}
+
+/*
+ * Begin an object or array (either top-level or nested within the currently
+ * open object or array).
+ */
+static inline void begin(struct json_writer *jw, char ch_open, int pretty)
+{
+	jw->pretty = pretty;
+
+	strbuf_addch(&jw->json, ch_open);
+
+	strbuf_addch(&jw->open_stack, ch_open);
+	strbuf_addch(&jw->first_stack, '1');
+}
+
+/*
+ * Assert that the top of the open-stack is an object.
+ */
+static inline void assert_in_object(const struct json_writer *jw, const char *key)
+{
+	if (!jw->open_stack.len)
+		BUG("json-writer: object: missing jw_object_begin(): '%s'", key);
+	if (jw->open_stack.buf[jw->open_stack.len - 1] != '{')
+		BUG("json-writer: object: not in object: '%s'", key);
+}
+
+/*
+ * Assert that the top of the open-stack is an array.
+ */
+static inline void assert_in_array(const struct json_writer *jw)
+{
+	if (!jw->open_stack.len)
+		BUG("json-writer: array: missing jw_array_begin()");
+	if (jw->open_stack.buf[jw->open_stack.len - 1] != '[')
+		BUG("json-writer: array: not in array");
+}
+
+/*
+ * Add comma if we have already seen a member at this level.
+ */
+static inline void maybe_add_comma(struct json_writer *jw)
+{
+	if (!jw->open_stack.len)
+		return;
+	if (jw->first_stack.buf[jw->first_stack.len - 1] == '1')
+		jw->first_stack.buf[jw->first_stack.len - 1] = '0';
+	else
+		strbuf_addch(&jw->json, ',');
+}
+
+static inline void fmt_double(struct json_writer *jw, int precision,
+			      double value)
+{
+	if (precision < 0) {
+		strbuf_addf(&jw->json, "%f", value);
+	} else {
+		struct strbuf fmt = STRBUF_INIT;
+		strbuf_addf(&fmt, "%%.%df", precision);
+		strbuf_addf(&jw->json, fmt.buf, value);
+		strbuf_release(&fmt);
+	}
+}
+
+static inline void object_common(struct json_writer *jw, const char *key)
+{
+	assert_in_object(jw, key);
+	maybe_add_comma(jw);
+
+	if (jw->pretty)
+		strbuf_addch(&jw->json, '\n');
+	indent_pretty(jw);
+
+	append_quoted_string(&jw->json, key);
+	strbuf_addch(&jw->json, ':');
+	if (jw->pretty)
+		strbuf_addch(&jw->json, ' ');
+}
+
+static inline void array_common(struct json_writer *jw)
+{
+	assert_in_array(jw);
+	maybe_add_comma(jw);
+
+	if (jw->pretty)
+		strbuf_addch(&jw->json, '\n');
+	indent_pretty(jw);
+}
+
+/*
+ * Assert that the given JSON object or JSON array has been properly
+ * terminated.  (Has closing bracket.)
+ */
+static inline void assert_is_terminated(const struct json_writer *jw)
+{
+	if (jw->open_stack.len)
+		BUG("json-writer: object: missing jw_end(): '%s'",
+		    jw->json.buf);
+}
+
+void jw_object_begin(struct json_writer *jw, int pretty)
+{
+	begin(jw, '{', pretty);
+}
+
+void jw_object_string(struct json_writer *jw, const char *key, const char *value)
+{
+	object_common(jw, key);
+	append_quoted_string(&jw->json, value);
+}
+
+void jw_object_intmax(struct json_writer *jw, const char *key, intmax_t value)
+{
+	object_common(jw, key);
+	strbuf_addf(&jw->json, "%"PRIdMAX, value);
+}
+
+void jw_object_double(struct json_writer *jw, const char *key, int precision,
+		      double value)
+{
+	object_common(jw, key);
+	fmt_double(jw, precision, value);
+}
+
+void jw_object_true(struct json_writer *jw, const char *key)
+{
+	object_common(jw, key);
+	strbuf_addstr(&jw->json, "true");
+}
+
+void jw_object_false(struct json_writer *jw, const char *key)
+{
+	object_common(jw, key);
+	strbuf_addstr(&jw->json, "false");
+}
+
+void jw_object_bool(struct json_writer *jw, const char *key, int value)
+{
+	if (value)
+		jw_object_true(jw, key);
+	else
+		jw_object_false(jw, key);
+}
+
+void jw_object_null(struct json_writer *jw, const char *key)
+{
+	object_common(jw, key);
+	strbuf_addstr(&jw->json, "null");
+}
+
+static void increase_indent(struct strbuf *sb,
+			    const struct json_writer *jw,
+			    int indent)
+{
+	int k;
+
+	strbuf_reset(sb);
+	for (k = 0; k < jw->json.len; k++) {
+		char ch = jw->json.buf[k];
+		strbuf_addch(sb, ch);
+		if (ch == '\n')
+			strbuf_addchars(sb, ' ', indent);
+	}
+}
+
+static void kill_indent(struct strbuf *sb,
+			const struct json_writer *jw)
+{
+	int k;
+	int eat_it = 0;
+
+	strbuf_reset(sb);
+	for (k = 0; k < jw->json.len; k++) {
+		char ch = jw->json.buf[k];
+		if (eat_it && ch == ' ')
+			continue;
+		if (ch == '\n') {
+			eat_it = 1;
+			continue;
+		}
+		eat_it = 0;
+		strbuf_addch(sb, ch);
+	}
+}
+
+static void append_sub_jw(struct json_writer *jw,
+			  const struct json_writer *value)
+{
+	/*
+	 * If both are pretty, increase the indentation of the sub_jw
+	 * to better fit under the super.
+	 *
+	 * If the super is pretty, but the sub_jw is compact, leave the
+	 * sub_jw compact.  (We don't want to parse and rebuild the sub_jw
+	 * for this debug-ish feature.)
+	 *
+	 * If the super is compact, and the sub_jw is pretty, convert
+	 * the sub_jw to compact.
+	 *
+	 * If both are compact, keep the sub_jw compact.
+	 */
+	if (jw->pretty && jw->open_stack.len && value->pretty) {
+		struct strbuf sb = STRBUF_INIT;
+		increase_indent(&sb, value, jw->open_stack.len * 2);
+		strbuf_addbuf(&jw->json, &sb);
+		strbuf_release(&sb);
+		return;
+	}
+	if (!jw->pretty && value->pretty) {
+		struct strbuf sb = STRBUF_INIT;
+		kill_indent(&sb, value);
+		strbuf_addbuf(&jw->json, &sb);
+		strbuf_release(&sb);
+		return;
+	}
+
+	strbuf_addbuf(&jw->json, &value->json);
+}
+
+/*
+ * Append existing (properly terminated) JSON sub-data (object or array)
+ * as-is onto the given JSON data.
+ */
+void jw_object_sub_jw(struct json_writer *jw, const char *key,
+		      const struct json_writer *value)
+{
+	assert_is_terminated(value);
+
+	object_common(jw, key);
+	append_sub_jw(jw, value);
+}
+
+void jw_object_inline_begin_object(struct json_writer *jw, const char *key)
+{
+	object_common(jw, key);
+
+	jw_object_begin(jw, jw->pretty);
+}
+
+void jw_object_inline_begin_array(struct json_writer *jw, const char *key)
+{
+	object_common(jw, key);
+
+	jw_array_begin(jw, jw->pretty);
+}
+
+void jw_array_begin(struct json_writer *jw, int pretty)
+{
+	begin(jw, '[', pretty);
+}
+
+void jw_array_string(struct json_writer *jw, const char *value)
+{
+	array_common(jw);
+	append_quoted_string(&jw->json, value);
+}
+
+void jw_array_intmax(struct json_writer *jw, intmax_t value)
+{
+	array_common(jw);
+	strbuf_addf(&jw->json, "%"PRIdMAX, value);
+}
+
+void jw_array_double(struct json_writer *jw, int precision, double value)
+{
+	array_common(jw);
+	fmt_double(jw, precision, value);
+}
+
+void jw_array_true(struct json_writer *jw)
+{
+	array_common(jw);
+	strbuf_addstr(&jw->json, "true");
+}
+
+void jw_array_false(struct json_writer *jw)
+{
+	array_common(jw);
+	strbuf_addstr(&jw->json, "false");
+}
+
+void jw_array_bool(struct json_writer *jw, int value)
+{
+	if (value)
+		jw_array_true(jw);
+	else
+		jw_array_false(jw);
+}
+
+void jw_array_null(struct json_writer *jw)
+{
+	array_common(jw);
+	strbuf_addstr(&jw->json, "null");
+}
+
+void jw_array_sub_jw(struct json_writer *jw, const struct json_writer *value)
+{
+	assert_is_terminated(value);
+
+	array_common(jw);
+	append_sub_jw(jw, value);
+}
+
+void jw_array_argc_argv(struct json_writer *jw, int argc, const char **argv)
+{
+	int k;
+
+	for (k = 0; k < argc; k++)
+		jw_array_string(jw, argv[k]);
+}
+
+void jw_array_argv(struct json_writer *jw, const char **argv)
+{
+	while (*argv)
+		jw_array_string(jw, *argv++);
+}
+
+void jw_array_inline_begin_object(struct json_writer *jw)
+{
+	array_common(jw);
+
+	jw_object_begin(jw, jw->pretty);
+}
+
+void jw_array_inline_begin_array(struct json_writer *jw)
+{
+	array_common(jw);
+
+	jw_array_begin(jw, jw->pretty);
+}
+
+int jw_is_terminated(const struct json_writer *jw)
+{
+	return !jw->open_stack.len;
+}
+
+void jw_end(struct json_writer *jw)
+{
+	char ch_open;
+	int len;
+
+	if (jw->open_stack.len != jw->first_stack.len)
+		BUG("jwon-writer: open_ and first_ stacks out of sync");
+	if (!jw->open_stack.len)
+		BUG("json-writer: too many jw_end(): '%s'", jw->json.buf);
+
+	len = jw->open_stack.len - 1;
+	ch_open = jw->open_stack.buf[len];
+
+	strbuf_setlen(&jw->open_stack, len);
+	strbuf_setlen(&jw->first_stack, len);
+
+	if (jw->pretty)
+		strbuf_addch(&jw->json, '\n');
+	indent_pretty(jw);
+
+	if (ch_open == '{')
+		strbuf_addch(&jw->json, '}');
+	else
+		strbuf_addch(&jw->json, ']');
+}
diff --git a/json-writer.h b/json-writer.h
new file mode 100644
index 0000000..af9c261
--- /dev/null
+++ b/json-writer.h
@@ -0,0 +1,113 @@
+#ifndef JSON_WRITER_H
+#define JSON_WRITER_H
+
+/*
+ * JSON data structures are defined at:
+ * [1] http://www.ietf.org/rfc/rfc7159.txt
+ * [2] http://json.org/
+ *
+ * The JSON-writer API allows one to build JSON data structures using a
+ * simple wrapper around a "struct strbuf" buffer.  It is intended as a
+ * simple API to build output strings; it is not intended to be a general
+ * object model for JSON data.  In particular, it does not re-order keys
+ * in an object (dictionary), it does not de-dup keys in an object, and
+ * it does not allow lookup or parsing of JSON data.
+ *
+ * All string values (both keys and string r-values) are properly quoted
+ * and escaped if they contain special characters.
+ *
+ * These routines create compact JSON data (with no unnecessary whitespace,
+ * newlines, or indenting).  If you get an unexpected response, verify
+ * that you're not expecting a pretty JSON string.
+ *
+ * Both "JSON objects" (aka sets of k/v pairs) and "JSON array" can be
+ * constructed using a 'begin append* end' model.
+ *
+ * Nested objects and arrays can either be constructed bottom up (by
+ * creating sub object/arrays first and appending them to the super
+ * object/array) -or- by building them inline in one pass.  This is a
+ * personal style and/or data shape choice.
+ *
+ * See t/helper/test-json-writer.c for various usage examples.
+ *
+ * LIMITATIONS:
+ * ============
+ *
+ * The JSON specification [1,2] defines string values as Unicode data
+ * and probably UTF-8 encoded.  The current json-writer API does not
+ * enforce this and will write any string as received.  However, it will
+ * properly quote and backslash-escape them as necessary.  It is up to
+ * the caller to UTF-8 encode their strings *before* passing them to this
+ * API.  This layer should not have to try to guess the encoding or locale
+ * of the given strings.
+ */
+
+struct json_writer
+{
+	/*
+	 * Buffer of the in-progress JSON currently being composed.
+	 */
+	struct strbuf json;
+
+	/*
+	 * Simple stack of the currently open array and object forms.
+	 * This is a string of '{' and '[' characters indicating the
+	 * currently unterminated forms.  This is used to ensure the
+	 * properly closing character is used when popping a level and
+	 * to know when the JSON is completely closed.
+	 */
+	struct strbuf open_stack;
+
+	/*
+	 * Another simple stack of the currently open array and object
+	 * forms.  This is used in parallel to "open_stack" (same length).
+	 * It contains a string of '1' and '0' where '1' indicates that
+	 * the next child-element seen will be the first child (and does
+	 * not need a leading comma).
+	 */
+	struct strbuf first_stack;
+
+	int pretty;
+};
+
+#define JSON_WRITER_INIT { STRBUF_INIT, STRBUF_INIT, STRBUF_INIT, 0 }
+
+void jw_init(struct json_writer *jw);
+void jw_release(struct json_writer *jw);
+
+void jw_object_begin(struct json_writer *jw, int pretty);
+void jw_array_begin(struct json_writer *jw, int pretty);
+
+void jw_object_string(struct json_writer *jw, const char *key,
+		      const char *value);
+void jw_object_intmax(struct json_writer *jw, const char *key, intmax_t value);
+void jw_object_double(struct json_writer *jw, const char *key, int precision,
+		      double value);
+void jw_object_true(struct json_writer *jw, const char *key);
+void jw_object_false(struct json_writer *jw, const char *key);
+void jw_object_bool(struct json_writer *jw, const char *key, int value);
+void jw_object_null(struct json_writer *jw, const char *key);
+void jw_object_sub_jw(struct json_writer *jw, const char *key,
+		      const struct json_writer *value);
+
+void jw_object_inline_begin_object(struct json_writer *jw, const char *key);
+void jw_object_inline_begin_array(struct json_writer *jw, const char *key);
+
+void jw_array_string(struct json_writer *jw, const char *value);
+void jw_array_intmax(struct json_writer *jw, intmax_t value);
+void jw_array_double(struct json_writer *jw, int precision, double value);
+void jw_array_true(struct json_writer *jw);
+void jw_array_false(struct json_writer *jw);
+void jw_array_bool(struct json_writer *jw, int value);
+void jw_array_null(struct json_writer *jw);
+void jw_array_sub_jw(struct json_writer *jw, const struct json_writer *value);
+void jw_array_argc_argv(struct json_writer *jw, int argc, const char **argv);
+void jw_array_argv(struct json_writer *jw, const char **argv);
+
+void jw_array_inline_begin_object(struct json_writer *jw);
+void jw_array_inline_begin_array(struct json_writer *jw);
+
+int jw_is_terminated(const struct json_writer *jw);
+void jw_end(struct json_writer *jw);
+
+#endif /* JSON_WRITER_H */
diff --git a/t/helper/test-json-writer.c b/t/helper/test-json-writer.c
new file mode 100644
index 0000000..5bc117c
--- /dev/null
+++ b/t/helper/test-json-writer.c
@@ -0,0 +1,572 @@
+#include "cache.h"
+#include "json-writer.h"
+
+static const char *expect_obj1 = "{\"a\":\"abc\",\"b\":42,\"c\":true}";
+static const char *expect_obj2 = "{\"a\":-1,\"b\":2147483647,\"c\":0}";
+static const char *expect_obj3 = "{\"a\":0,\"b\":4294967295,\"c\":9223372036854775807}";
+static const char *expect_obj4 = "{\"t\":true,\"f\":false,\"n\":null}";
+static const char *expect_obj5 = "{\"abc\\tdef\":\"abc\\\\def\"}";
+static const char *expect_obj6 = "{\"a\":3.14}";
+
+static const char *pretty_obj1 = ("{\n"
+				  "  \"a\": \"abc\",\n"
+				  "  \"b\": 42,\n"
+				  "  \"c\": true\n"
+				  "}");
+static const char *pretty_obj2 = ("{\n"
+				  "  \"a\": -1,\n"
+				  "  \"b\": 2147483647,\n"
+				  "  \"c\": 0\n"
+				  "}");
+static const char *pretty_obj3 = ("{\n"
+				  "  \"a\": 0,\n"
+				  "  \"b\": 4294967295,\n"
+				  "  \"c\": 9223372036854775807\n"
+				  "}");
+static const char *pretty_obj4 = ("{\n"
+				  "  \"t\": true,\n"
+				  "  \"f\": false,\n"
+				  "  \"n\": null\n"
+				  "}");
+
+static struct json_writer obj1 = JSON_WRITER_INIT;
+static struct json_writer obj2 = JSON_WRITER_INIT;
+static struct json_writer obj3 = JSON_WRITER_INIT;
+static struct json_writer obj4 = JSON_WRITER_INIT;
+static struct json_writer obj5 = JSON_WRITER_INIT;
+static struct json_writer obj6 = JSON_WRITER_INIT;
+
+static void make_obj1(int pretty)
+{
+	jw_object_begin(&obj1, pretty);
+	{
+		jw_object_string(&obj1, "a", "abc");
+		jw_object_intmax(&obj1, "b", 42);
+		jw_object_true(&obj1, "c");
+	}
+	jw_end(&obj1);
+}
+
+static void make_obj2(int pretty)
+{
+	jw_object_begin(&obj2, pretty);
+	{
+		jw_object_intmax(&obj2, "a", -1);
+		jw_object_intmax(&obj2, "b", 0x7fffffff);
+		jw_object_intmax(&obj2, "c", 0);
+	}
+	jw_end(&obj2);
+}
+
+static void make_obj3(int pretty)
+{
+	jw_object_begin(&obj3, pretty);
+	{
+		jw_object_intmax(&obj3, "a", 0);
+		jw_object_intmax(&obj3, "b", 0xffffffff);
+		jw_object_intmax(&obj3, "c", 0x7fffffffffffffffULL);
+	}
+	jw_end(&obj3);
+}
+
+static void make_obj4(int pretty)
+{
+	jw_object_begin(&obj4, pretty);
+	{
+		jw_object_true(&obj4, "t");
+		jw_object_false(&obj4, "f");
+		jw_object_null(&obj4, "n");
+	}
+	jw_end(&obj4);
+}
+
+static void make_obj5(int pretty)
+{
+	jw_object_begin(&obj5, pretty);
+	{
+		jw_object_string(&obj5, "abc" "\x09" "def", "abc" "\\" "def");
+	}
+	jw_end(&obj5);
+}
+
+static void make_obj6(int pretty)
+{
+	jw_object_begin(&obj6, pretty);
+	{
+		jw_object_double(&obj6, "a", 2, 3.14159);
+	}
+	jw_end(&obj6);
+}
+
+static const char *expect_arr1 = "[\"abc\",42,true]";
+static const char *expect_arr2 = "[-1,2147483647,0]";
+static const char *expect_arr3 = "[0,4294967295,9223372036854775807]";
+static const char *expect_arr4 = "[true,false,null]";
+
+static const char *pretty_arr1 = ("[\n"
+				  "  \"abc\",\n"
+				  "  42,\n"
+				  "  true\n"
+				  "]");
+static const char *pretty_arr2 = ("[\n"
+				  "  -1,\n"
+				  "  2147483647,\n"
+				  "  0\n"
+				  "]");
+static const char *pretty_arr3 = ("[\n"
+				  "  0,\n"
+				  "  4294967295,\n"
+				  "  9223372036854775807\n"
+				  "]");
+static const char *pretty_arr4 = ("[\n"
+				  "  true,\n"
+				  "  false,\n"
+				  "  null\n"
+				  "]");
+
+static struct json_writer arr1 = JSON_WRITER_INIT;
+static struct json_writer arr2 = JSON_WRITER_INIT;
+static struct json_writer arr3 = JSON_WRITER_INIT;
+static struct json_writer arr4 = JSON_WRITER_INIT;
+
+static void make_arr1(int pretty)
+{
+	jw_array_begin(&arr1, pretty);
+	{
+		jw_array_string(&arr1, "abc");
+		jw_array_intmax(&arr1, 42);
+		jw_array_true(&arr1);
+	}
+	jw_end(&arr1);
+}
+
+static void make_arr2(int pretty)
+{
+	jw_array_begin(&arr2, pretty);
+	{
+		jw_array_intmax(&arr2, -1);
+		jw_array_intmax(&arr2, 0x7fffffff);
+		jw_array_intmax(&arr2, 0);
+	}
+	jw_end(&arr2);
+}
+
+static void make_arr3(int pretty)
+{
+	jw_array_begin(&arr3, pretty);
+	{
+		jw_array_intmax(&arr3, 0);
+		jw_array_intmax(&arr3, 0xffffffff);
+		jw_array_intmax(&arr3, 0x7fffffffffffffffULL);
+	}
+	jw_end(&arr3);
+}
+
+static void make_arr4(int pretty)
+{
+	jw_array_begin(&arr4, pretty);
+	{
+		jw_array_true(&arr4);
+		jw_array_false(&arr4);
+		jw_array_null(&arr4);
+	}
+	jw_end(&arr4);
+}
+
+static char *expect_nest1 =
+	"{\"obj1\":{\"a\":\"abc\",\"b\":42,\"c\":true},\"arr1\":[\"abc\",42,true]}";
+
+static struct json_writer nest1 = JSON_WRITER_INIT;
+
+static void make_nest1(int pretty)
+{
+	jw_object_begin(&nest1, pretty);
+	{
+		jw_object_sub_jw(&nest1, "obj1", &obj1);
+		jw_object_sub_jw(&nest1, "arr1", &arr1);
+	}
+	jw_end(&nest1);
+}
+
+static char *expect_inline1 =
+	"{\"obj1\":{\"a\":\"abc\",\"b\":42,\"c\":true},\"arr1\":[\"abc\",42,true]}";
+
+static char *pretty_inline1 =
+	("{\n"
+	 "  \"obj1\": {\n"
+	 "    \"a\": \"abc\",\n"
+	 "    \"b\": 42,\n"
+	 "    \"c\": true\n"
+	 "  },\n"
+	 "  \"arr1\": [\n"
+	 "    \"abc\",\n"
+	 "    42,\n"
+	 "    true\n"
+	 "  ]\n"
+	 "}");
+
+static struct json_writer inline1 = JSON_WRITER_INIT;
+
+static void make_inline1(int pretty)
+{
+	jw_object_begin(&inline1, pretty);
+	{
+		jw_object_inline_begin_object(&inline1, "obj1");
+		{
+			jw_object_string(&inline1, "a", "abc");
+			jw_object_intmax(&inline1, "b", 42);
+			jw_object_true(&inline1, "c");
+		}
+		jw_end(&inline1);
+		jw_object_inline_begin_array(&inline1, "arr1");
+		{
+			jw_array_string(&inline1, "abc");
+			jw_array_intmax(&inline1, 42);
+			jw_array_true(&inline1);
+		}
+		jw_end(&inline1);
+	}
+	jw_end(&inline1);
+}
+
+static char *expect_inline2 =
+	"[[1,2],[3,4],{\"a\":\"abc\"}]";
+
+static char *pretty_inline2 =
+	("[\n"
+	 "  [\n"
+	 "    1,\n"
+	 "    2\n"
+	 "  ],\n"
+	 "  [\n"
+	 "    3,\n"
+	 "    4\n"
+	 "  ],\n"
+	 "  {\n"
+	 "    \"a\": \"abc\"\n"
+	 "  }\n"
+	 "]");
+
+static struct json_writer inline2 = JSON_WRITER_INIT;
+
+static void make_inline2(int pretty)
+{
+	jw_array_begin(&inline2, pretty);
+	{
+		jw_array_inline_begin_array(&inline2);
+		{
+			jw_array_intmax(&inline2, 1);
+			jw_array_intmax(&inline2, 2);
+		}
+		jw_end(&inline2);
+		jw_array_inline_begin_array(&inline2);
+		{
+			jw_array_intmax(&inline2, 3);
+			jw_array_intmax(&inline2, 4);
+		}
+		jw_end(&inline2);
+		jw_array_inline_begin_object(&inline2);
+		{
+			jw_object_string(&inline2, "a", "abc");
+		}
+		jw_end(&inline2);
+	}
+	jw_end(&inline2);
+}
+
+/*
+ * When super is compact, we expect subs to be compacted (even if originally
+ * pretty).
+ */
+static const char *expect_mixed1 =
+	("{\"obj1\":{\"a\":\"abc\",\"b\":42,\"c\":true},"
+	 "\"arr1\":[\"abc\",42,true]}");
+
+/*
+ * When super is pretty, a compact sub (obj1) is kept compact and a pretty
+ * sub (arr1) is re-indented.
+ */
+static const char *pretty_mixed1 =
+	("{\n"
+	 "  \"obj1\": {\"a\":\"abc\",\"b\":42,\"c\":true},\n"
+	 "  \"arr1\": [\n"
+	 "    \"abc\",\n"
+	 "    42,\n"
+	 "    true\n"
+	 "  ]\n"
+	 "}");
+
+static struct json_writer mixed1 = JSON_WRITER_INIT;
+
+static void make_mixed1(int pretty)
+{
+	jw_init(&obj1);
+	jw_init(&arr1);
+
+	make_obj1(0); /* obj1 is compact */
+	make_arr1(1); /* arr1 is pretty */
+
+	jw_object_begin(&mixed1, pretty);
+	{
+		jw_object_sub_jw(&mixed1, "obj1", &obj1);
+		jw_object_sub_jw(&mixed1, "arr1", &arr1);
+	}
+	jw_end(&mixed1);
+}
+
+static void cmp(const char *test, const struct json_writer *jw, const char *exp)
+{
+	if (!strcmp(jw->json.buf, exp))
+		return;
+
+	printf("error[%s]: observed '%s' expected '%s'\n",
+	       test, jw->json.buf, exp);
+	exit(1);
+}
+
+#define t(v) do { make_##v(0); cmp(#v, &v, expect_##v); } while (0)
+#define p(v) do { make_##v(1); cmp(#v, &v, pretty_##v); } while (0)
+
+/*
+ * Run some basic regression tests with some known patterns.
+ * These tests also demonstrate how to use the jw_ API.
+ */
+static int unit_tests(void)
+{
+	/* comptact (canonical) forms */
+	t(obj1);
+	t(obj2);
+	t(obj3);
+	t(obj4);
+	t(obj5);
+	t(obj6);
+
+	t(arr1);
+	t(arr2);
+	t(arr3);
+	t(arr4);
+
+	t(nest1);
+
+	t(inline1);
+	t(inline2);
+
+	jw_init(&obj1);
+	jw_init(&obj2);
+	jw_init(&obj3);
+	jw_init(&obj4);
+
+	jw_init(&arr1);
+	jw_init(&arr2);
+	jw_init(&arr3);
+	jw_init(&arr4);
+
+	jw_init(&inline1);
+	jw_init(&inline2);
+
+	/* pretty forms */
+	p(obj1);
+	p(obj2);
+	p(obj3);
+	p(obj4);
+
+	p(arr1);
+	p(arr2);
+	p(arr3);
+	p(arr4);
+
+	p(inline1);
+	p(inline2);
+
+	/* mixed forms */
+	t(mixed1);
+	jw_init(&mixed1);
+	p(mixed1);
+
+	return 0;
+}
+
+#define STMT(s) do { s } while (0)
+
+#define PARAM(tok, lbl, p) \
+	STMT( if (!(p) || (*(p) == '@')) \
+		die("token '%s' requires '%s' parameter, but saw: '%s'", \
+		    tok, lbl, p); )
+
+#define KEY() \
+	STMT( key = argv[++k]; \
+	      PARAM(a_k, "key", key); )
+
+#define VAL() \
+	STMT( val = argv[++k]; \
+	      PARAM(a_k, "val", val); )
+
+#define PRECISION() \
+	STMT( const char *s = argv[++k]; \
+	      PARAM(a_k, "precision", s); \
+	      precision = strtol(s, &endptr, 10); \
+	      if (*endptr || errno == ERANGE) \
+		die("invalid '%s' precision: '%s'", a_k, s); )
+
+#define VAL_INTMAX() \
+	STMT( VAL(); \
+	      v_int = strtol(val, &endptr, 10); \
+	      if (*endptr || errno == ERANGE) \
+		die("invalid '%s' value: '%s'",	a_k, val); )
+
+#define VAL_DOUBLE() \
+	STMT( VAL(); \
+	      v_double = strtod(val, &endptr); \
+	      if (*endptr || errno == ERANGE) \
+		die("invalid '%s' value: '%s'",	a_k, val); )
+
+static int pretty;
+
+static inline int scripted(int argc, const char **argv)
+{
+	struct json_writer jw = JSON_WRITER_INIT;
+	int k;
+
+	if (!strcmp(argv[0], "@object"))
+		jw_object_begin(&jw, pretty);
+	else if (!strcmp(argv[0], "@array"))
+		jw_array_begin(&jw, pretty);
+	else
+		die("expected '@object' or '@array': '%s'", argv[0]);
+
+	for (k = 1; k < argc; k++) {
+		const char *a_k = argv[k];
+		const char *key;
+		const char *val;
+		char *endptr;
+		int precision;
+		intmax_t v_int;
+		double v_double;
+
+		if (!strcmp(a_k, "@end")) {
+			jw_end(&jw);
+			continue;
+		}
+
+		if (!strcmp(a_k, "@object-string")) {
+			KEY();
+			VAL();
+			jw_object_string(&jw, key, val);
+			continue;
+		}
+		if (!strcmp(a_k, "@object-int")) {
+			KEY();
+			VAL_INTMAX();
+			jw_object_intmax(&jw, key, v_int);
+			continue;
+		}
+		if (!strcmp(a_k, "@object-double")) {
+			KEY();
+			PRECISION();
+			VAL_DOUBLE();
+			jw_object_double(&jw, key, precision, v_double);
+			continue;
+		}
+		if (!strcmp(a_k, "@object-true")) {
+			KEY();
+			jw_object_true(&jw, key);
+			continue;
+		}
+		if (!strcmp(a_k, "@object-false")) {
+			KEY();
+			jw_object_false(&jw, key);
+			continue;
+		}
+		if (!strcmp(a_k, "@object-null")) {
+			KEY();
+			jw_object_null(&jw, key);
+			continue;
+		}
+		if (!strcmp(a_k, "@object-object")) {
+			KEY();
+			jw_object_inline_begin_object(&jw, key);
+			continue;
+		}
+		if (!strcmp(a_k, "@object-array")) {
+			KEY();
+			jw_object_inline_begin_array(&jw, key);
+			continue;
+		}
+
+		if (!strcmp(a_k, "@array-string")) {
+			VAL();
+			jw_array_string(&jw, val);
+			continue;
+		}
+		if (!strcmp(a_k, "@array-int")) {
+			VAL_INTMAX();
+			jw_array_intmax(&jw, v_int);
+			continue;
+		}
+		if (!strcmp(a_k, "@array-double")) {
+			PRECISION();
+			VAL_DOUBLE();
+			jw_array_double(&jw, precision, v_double);
+			continue;
+		}
+		if (!strcmp(a_k, "@array-true")) {
+			jw_array_true(&jw);
+			continue;
+		}
+		if (!strcmp(a_k, "@array-false")) {
+			jw_array_false(&jw);
+			continue;
+		}
+		if (!strcmp(a_k, "@array-null")) {
+			jw_array_null(&jw);
+			continue;
+		}
+		if (!strcmp(a_k, "@array-object")) {
+			jw_array_inline_begin_object(&jw);
+			continue;
+		}
+		if (!strcmp(a_k, "@array-array")) {
+			jw_array_inline_begin_array(&jw);
+			continue;
+		}
+
+		die("unrecognized token: '%s'", a_k);
+	}
+
+	if (!jw_is_terminated(&jw))
+		die("json not terminated: '%s'", jw.json.buf);
+
+	printf("%s\n", jw.json.buf);
+
+	strbuf_release(&jw.json);
+	return 0;
+}
+
+static inline int my_usage(void)
+{
+	die("usage: '-u' | '[-p] @object ... @end' | '[-p] @array ... @end'");
+}
+
+int cmd_main(int argc, const char **argv)
+{
+	if (argc <= 1)
+		return my_usage();
+
+	argc--;
+	argv++;
+
+	if (argv[0][0] == '-') {
+		if (!strcmp(argv[0], "-u") || !strcmp(argv[0], "--unit"))
+			return unit_tests();
+
+		if (!strcmp(argv[0], "-p") || !strcmp(argv[0], "--pretty")) {
+			pretty = 1;
+			argc--;
+			argv++;
+			if (argc < 1)
+				return my_usage();
+		}
+	}
+
+	return scripted(argc, argv);
+}
diff --git a/t/t0019-json-writer.sh b/t/t0019-json-writer.sh
new file mode 100755
index 0000000..c9c2e23
--- /dev/null
+++ b/t/t0019-json-writer.sh
@@ -0,0 +1,236 @@
+#!/bin/sh
+
+test_description='test json-writer JSON generation'
+. ./test-lib.sh
+
+test_expect_success 'unit test of json-writer routines' '
+	test-json-writer -u
+'
+
+test_expect_success 'trivial object' '
+	cat >expect <<-\EOF &&
+	{}
+	EOF
+	test-json-writer >actual \
+		@object \
+		@end &&
+	test_cmp expect actual
+'
+
+test_expect_success 'trivial array' '
+	cat >expect <<-\EOF &&
+	[]
+	EOF
+	test-json-writer >actual \
+		@array \
+		@end &&
+	test_cmp expect actual
+'
+
+test_expect_success 'simple object' '
+	cat >expect <<-\EOF &&
+	{"a":"abc","b":42,"c":3.14,"d":true,"e":false,"f":null}
+	EOF
+	test-json-writer >actual \
+		@object \
+			@object-string a abc \
+			@object-int b 42 \
+			@object-double c 2 3.140 \
+			@object-true d \
+			@object-false e \
+			@object-null f \
+		@end &&
+	test_cmp expect actual
+'
+
+test_expect_success 'simple array' '
+	cat >expect <<-\EOF &&
+	["abc",42,3.14,true,false,null]
+	EOF
+	test-json-writer >actual \
+		@array \
+			@array-string abc \
+			@array-int 42 \
+			@array-double 2 3.140 \
+			@array-true \
+			@array-false \
+			@array-null \
+		@end &&
+	test_cmp expect actual
+'
+
+test_expect_success 'escape quoting string' '
+	cat >expect <<-\EOF &&
+	{"a":"abc\\def"}
+	EOF
+	test-json-writer >actual \
+		@object \
+			@object-string a abc\\def \
+		@end &&
+	test_cmp expect actual
+'
+
+test_expect_success 'escape quoting string 2' '
+	cat >expect <<-\EOF &&
+	{"a":"abc\"def"}
+	EOF
+	test-json-writer >actual \
+		@object \
+			@object-string a abc\"def \
+		@end &&
+	test_cmp expect actual
+'
+
+test_expect_success 'nested inline object' '
+	cat >expect <<-\EOF &&
+	{"a":"abc","b":42,"sub1":{"c":3.14,"d":true,"sub2":{"e":false,"f":null}}}
+	EOF
+	test-json-writer >actual \
+		@object \
+			@object-string a abc \
+			@object-int b 42 \
+			@object-object "sub1" \
+				@object-double c 2 3.140 \
+				@object-true d \
+				@object-object "sub2" \
+					@object-false e \
+					@object-null f \
+				@end \
+			@end \
+		@end &&
+	test_cmp expect actual
+'
+
+test_expect_success 'nested inline array' '
+	cat >expect <<-\EOF &&
+	["abc",42,[3.14,true,[false,null]]]
+	EOF
+	test-json-writer >actual \
+		@array \
+			@array-string abc \
+			@array-int 42 \
+			@array-array \
+				@array-double 2 3.140 \
+				@array-true \
+				@array-array \
+					@array-false \
+					@array-null \
+				@end \
+			@end \
+		@end &&
+	test_cmp expect actual
+'
+
+test_expect_success 'nested inline object and array' '
+	cat >expect <<-\EOF &&
+	{"a":"abc","b":42,"sub1":{"c":3.14,"d":true,"sub2":[false,null]}}
+	EOF
+	test-json-writer >actual \
+		@object \
+			@object-string a abc \
+			@object-int b 42 \
+			@object-object "sub1" \
+				@object-double c 2 3.140 \
+				@object-true d \
+				@object-array "sub2" \
+					@array-false \
+					@array-null \
+				@end \
+			@end \
+		@end &&
+	test_cmp expect actual
+'
+
+test_expect_success 'nested inline object and array 2' '
+	cat >expect <<-\EOF &&
+	{"a":"abc","b":42,"sub1":{"c":3.14,"d":true,"sub2":[false,{"g":0,"h":1},null]}}
+	EOF
+	test-json-writer >actual \
+		@object \
+			@object-string a abc \
+			@object-int b 42 \
+			@object-object "sub1" \
+				@object-double c 2 3.140 \
+				@object-true d \
+				@object-array "sub2" \
+					@array-false \
+					@array-object \
+						@object-int g 0 \
+						@object-int h 1 \
+					@end \
+					@array-null \
+				@end \
+			@end \
+		@end &&
+	test_cmp expect actual
+'
+
+test_expect_success 'pretty nested inline object and array 2' '
+	sed -e "s/^|//" >expect <<-\EOF &&
+	|{
+	|  "a": "abc",
+	|  "b": 42,
+	|  "sub1": {
+	|    "c": 3.14,
+	|    "d": true,
+	|    "sub2": [
+	|      false,
+	|      {
+	|        "g": 0,
+	|        "h": 1
+	|      },
+	|      null
+	|    ]
+	|  }
+	|}
+	EOF
+	test-json-writer >actual \
+		--pretty \
+		@object \
+			@object-string a abc \
+			@object-int b 42 \
+			@object-object "sub1" \
+				@object-double c 2 3.140 \
+				@object-true d \
+				@object-array "sub2" \
+					@array-false \
+					@array-object \
+						@object-int g 0 \
+						@object-int h 1 \
+					@end \
+					@array-null \
+				@end \
+			@end \
+		@end &&
+	test_cmp expect actual
+'
+
+test_expect_success 'inline object with no members' '
+	cat >expect <<-\EOF &&
+	{"a":"abc","empty":{},"b":42}
+	EOF
+	test-json-writer >actual \
+		@object \
+			@object-string a abc \
+			@object-object "empty" \
+			@end \
+			@object-int b 42 \
+		@end &&
+	test_cmp expect actual
+'
+
+test_expect_success 'inline array with no members' '
+	cat >expect <<-\EOF &&
+	{"a":"abc","empty":[],"b":42}
+	EOF
+	test-json-writer >actual \
+		@object \
+			@object-string a abc \
+			@object-array "empty" \
+			@end \
+			@object-int b 42 \
+		@end &&
+	test_cmp expect actual
+'
+
+test_done
-- 
2.9.3

[PATCH v7 2/2] json-writer: t0019: add Python unit test

[git]

From: Jeff Hostetler <jeffhost@microsoft.com>

Test json-writer output using Python.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
---
 t/t0019-json-writer.sh  | 38 ++++++++++++++++++++++++++++++++++++++
 t/t0019/parse_json_1.py | 35 +++++++++++++++++++++++++++++++++++
 2 files changed, 73 insertions(+)
 create mode 100644 t/t0019/parse_json_1.py

diff --git a/t/t0019-json-writer.sh b/t/t0019-json-writer.sh
index c9c2e23..951cd89 100755
--- a/t/t0019-json-writer.sh
+++ b/t/t0019-json-writer.sh
@@ -233,4 +233,42 @@ test_expect_success 'inline array with no members' '
 	test_cmp expect actual
 '
 
+# As a sanity check, ask Python to parse our generated JSON.  Let Python
+# recursively dump the resulting dictionary in sorted order.  Confirm that
+# that matches our expectations.
+test_expect_success PYTHON 'parse JSON using Python' '
+	cat >expect <<-\EOF &&
+	a abc
+	b 42
+	sub1 dict
+	sub1.c 3.14
+	sub1.d True
+	sub1.sub2 list
+	sub1.sub2[0] False
+	sub1.sub2[1] dict
+	sub1.sub2[1].g 0
+	sub1.sub2[1].h 1
+	sub1.sub2[2] None
+	EOF
+	test-json-writer >output.json \
+		@object \
+			@object-string a abc \
+			@object-int b 42 \
+			@object-object "sub1" \
+				@object-double c 2 3.140 \
+				@object-true d \
+				@object-array "sub2" \
+					@array-false \
+					@array-object \
+						@object-int g 0 \
+						@object-int h 1 \
+					@end \
+					@array-null \
+				@end \
+			@end \
+		@end &&
+	python "$TEST_DIRECTORY"/t0019/parse_json_1.py <output.json >actual &&
+	test_cmp expect actual
+'
+
 test_done
diff --git a/t/t0019/parse_json_1.py b/t/t0019/parse_json_1.py
new file mode 100644
index 0000000..9d928a3
--- /dev/null
+++ b/t/t0019/parse_json_1.py
@@ -0,0 +1,35 @@
+import os
+import sys
+import json
+
+def dump_item(label_input, v):
+    if type(v) is dict:
+        print("%s dict" % (label_input))
+        dump_dict(label_input, v)
+    elif type(v) is list:
+        print("%s list" % (label_input))
+        dump_list(label_input, v)
+    else:
+        print("%s %s" % (label_input, v))
+
+def dump_list(label_input, list_input):
+    ix = 0
+    for v in list_input:
+        label = ("%s[%d]" % (label_input, ix))
+        dump_item(label, v)
+        ix += 1
+    return
+              
+def dump_dict(label_input, dict_input):
+    for k in sorted(dict_input.iterkeys()):
+        v = dict_input[k]
+        if (len(label_input) > 0):
+            label = ("%s.%s" % (label_input, k))
+        else:
+            label = k
+        dump_item(label, v)
+    return
+
+for line in sys.stdin:
+    data = json.loads(line)
+    dump_dict("", data)
-- 
2.9.3

Re: [PATCH v7 2/2] json-writer: t0019: add Python unit test

[Todd Zullinger]

git@jeffhostetler.com wrote:
> +# As a sanity check, ask Python to parse our generated JSON.  Let Python
> +# recursively dump the resulting dictionary in sorted order.  Confirm that
> +# that matches our expectations.
> +test_expect_success PYTHON 'parse JSON using Python' '
[...]
> +	python "$TEST_DIRECTORY"/t0019/parse_json_1.py <output.json >actual &&

Would this be better using $PYTHON_PATH rather than
hard-coding python as the command?

-- 
Todd
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Sometimes I think I understand everything, then I regain
consciousness.

Re: [PATCH v7 2/2] json-writer: t0019: add Python unit test

[Jeff King]

On Wed, Jun 06, 2018 at 01:10:52PM -0400, Todd Zullinger wrote:

> git@jeffhostetler.com wrote:
> > +# As a sanity check, ask Python to parse our generated JSON.  Let Python
> > +# recursively dump the resulting dictionary in sorted order.  Confirm that
> > +# that matches our expectations.
> > +test_expect_success PYTHON 'parse JSON using Python' '
> [...]
> > +	python "$TEST_DIRECTORY"/t0019/parse_json_1.py <output.json >actual &&
> 
> Would this be better using $PYTHON_PATH rather than
> hard-coding python as the command?

Probably. We may want to go the same route as we did for perl in 
a0e0ec9f7d (t: provide a perl() function which uses $PERL_PATH,
2013-10-28) so that test writers don't have to remember this.

That said, I wonder if it would be hard to simply do the python bits
here in perl. This is the first use of python in our test scripts (and
really the only user in the whole code base outside of a few fringe
commands). Leaving aside any perl vs python flame-war, I think there's
value in keeping the number of languages limited when there's not a
compelling reason to do otherwise.

-Peff

Re: [PATCH v7 2/2] json-writer: t0019: add Python unit test

[Jeff Hostetler]

On 6/6/2018 5:03 PM, Jeff King wrote:
> On Wed, Jun 06, 2018 at 01:10:52PM -0400, Todd Zullinger wrote:
> 
>> git@jeffhostetler.com wrote:
>>> +# As a sanity check, ask Python to parse our generated JSON.  Let Python
>>> +# recursively dump the resulting dictionary in sorted order.  Confirm that
>>> +# that matches our expectations.
>>> +test_expect_success PYTHON 'parse JSON using Python' '
>> [...]
>>> +	python "$TEST_DIRECTORY"/t0019/parse_json_1.py <output.json >actual &&
>>
>> Would this be better using $PYTHON_PATH rather than
>> hard-coding python as the command?
> 
> Probably. We may want to go the same route as we did for perl in
> a0e0ec9f7d (t: provide a perl() function which uses $PERL_PATH,
> 2013-10-28) so that test writers don't have to remember this.
> 
> That said, I wonder if it would be hard to simply do the python bits
> here in perl. This is the first use of python in our test scripts (and
> really the only user in the whole code base outside of a few fringe
> commands). Leaving aside any perl vs python flame-war, I think there's
> value in keeping the number of languages limited when there's not a
> compelling reason to do otherwise.
> 

Perl works too.  (I don't know perl, but I'm told it does work for
stuff like this. :-)

I'll take a stab at it.

Jeff

Re: [PATCH v7 2/2] json-writer: t0019: add Python unit test

[Ramsay Jones]

On 06/06/18 22:03, Jeff King wrote:
> On Wed, Jun 06, 2018 at 01:10:52PM -0400, Todd Zullinger wrote:
> 
>> git@jeffhostetler.com wrote:
>>> +# As a sanity check, ask Python to parse our generated JSON.  Let Python
>>> +# recursively dump the resulting dictionary in sorted order.  Confirm that
>>> +# that matches our expectations.
>>> +test_expect_success PYTHON 'parse JSON using Python' '
>> [...]
>>> +	python "$TEST_DIRECTORY"/t0019/parse_json_1.py <output.json >actual &&
>>
>> Would this be better using $PYTHON_PATH rather than
>> hard-coding python as the command?
> 
> Probably. We may want to go the same route as we did for perl in 
> a0e0ec9f7d (t: provide a perl() function which uses $PERL_PATH,
> 2013-10-28) so that test writers don't have to remember this.
> 
> That said, I wonder if it would be hard to simply do the python bits
> here in perl. This is the first use of python in our test scripts (and

Hmm, not quite the _first_ use:

$ git grep PYTHON_PATH -- t
t/lib-git-p4.sh:        (cd / && "$PYTHON_PATH" -c 'import time; print(int(time.time()))')
t/lib-git-p4.sh:        "$PYTHON_PATH" "$TRASH_DIRECTORY/marshal-dump.py"
t/t9020-remote-svn.sh:export PATH PYTHON_PATH GIT_BUILD_DIR
t/t9020-remote-svn.sh:exec "$PYTHON_PATH" "$GIT_BUILD_DIR/contrib/svn-fe/svnrdump_sim.py" "$@"
t/t9802-git-p4-filetype.sh:             "$PYTHON_PATH" "$TRASH_DIRECTORY/k_smush.py" <"$cli/k-text-k" >cli-k-text-k-smush &&
t/t9802-git-p4-filetype.sh:             "$PYTHON_PATH" "$TRASH_DIRECTORY/ko_smush.py" <"$cli/k-text-ko" >cli-k-text-ko-smush &&
t/t9802-git-p4-filetype.sh:             "$PYTHON_PATH" "$TRASH_DIRECTORY/gendouble.py" >%double.png &&
t/t9810-git-p4-rcs.sh:  "$PYTHON_PATH" "$TRASH_DIRECTORY/scrub_k.py" <"$git/$file" >"$scrub" &&
t/t9810-git-p4-rcs.sh:  "$PYTHON_PATH" "$TRASH_DIRECTORY/scrub_ko.py" <"$git/$file" >"$scrub" &&
$ 

I don't run the p4 or svn tests, so ... :-D

> really the only user in the whole code base outside of a few fringe
> commands). Leaving aside any perl vs python flame-war, I think there's
> value in keeping the number of languages limited when there's not a
> compelling reason to do otherwise.

I agree that fewer languages is (generally) a good idea.

ATB,
Ramsay Jones

Re: [PATCH v7 2/2] json-writer: t0019: add Python unit test

[Todd Zullinger]

Ramsay Jones wrote:
[...]
> I don't run the p4 or svn tests, so ... :-D

Heh, lucky you. :)

I try to run them all as part of the fedora builds since
they cover much more than I'd ever use.  That's the main
reason I noticed the bare python.  That would trip me up
when it came time to build on a near-future fedora where
python isn't installed by default and I only wanted to
require python3 for the build/runtime scripts.

> On 06/06/18 22:03, Jeff King wrote:
>> really the only user in the whole code base outside of a few fringe
>> commands). Leaving aside any perl vs python flame-war, I think there's
>> value in keeping the number of languages limited when there's not a
>> compelling reason to do otherwise.
> 
> I agree that fewer languages is (generally) a good idea.

Yep, that's certainly even better and if Jeff H. can use
perl relatively easily (or one of the many perl folks here
can help with that part of the test), that's great.  The
best way to solve many problems is avoid having them. :)

Thanks,

-- 
Todd
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Chaos, panic, and disorder - my job is done here.

Re: [PATCH v7 2/2] json-writer: t0019: add Python unit test

[Jeff King]

On Wed, Jun 06, 2018 at 09:49:09PM -0400, Todd Zullinger wrote:

> Ramsay Jones wrote:
> [...]
> > I don't run the p4 or svn tests, so ... :-D
> 
> Heh, lucky you. :)
> 
> I try to run them all as part of the fedora builds since
> they cover much more than I'd ever use.  That's the main
> reason I noticed the bare python.  That would trip me up
> when it came time to build on a near-future fedora where
> python isn't installed by default and I only wanted to
> require python3 for the build/runtime scripts.

I'm not actually sure those svn bits involving python are usable by real
users. The main tool that people us for svn interop is git-svn, which is
written in perl.

There was an effort to have a real "git-remote-svn" helper (so that you
could just seamlessly "git clone svn://..." instead of using the "git
svn" wrapper.

So we have the work in vcs-svn, which gets built as part of a regular
compile. But AFAICT it is only used for git-remote-testsvn,
t/helper/test-svn-fe, and contrib/svn-fe. None of which have seen any
substantive work since 2012[1].

I suppose it's possible somebody could be using "git clone testsvn://"
in the wild, but the name would hopefully warn them off. I have no idea
how usable that work is in practice.

-Peff

[1] Browsing "git log", most of the commits are just tree-wide
    cleanups, or fixing some compilation or dependency error. The last
    "real" commit seems to be around 8e43a1d010 (remote-svn: add
    incremental import, 2012-09-19).

    I wonder if it is worth dropping this experiment as incomplete and
    unmaintained. People have obviously spent time dealing with the code
    for various fixups, but I think the whole thing may essentially just
    be dead code. Or maybe people really are using contrib/svn-fe. Like
    I said, I have no clue if this stuff is even usable, but we
    certainly haven't packaged it to be seen by most users.

Re: [PATCH v7 2/2] json-writer: t0019: add Python unit test

[Jeff King]

On Thu, Jun 07, 2018 at 01:16:14AM +0100, Ramsay Jones wrote:

> > Probably. We may want to go the same route as we did for perl in 
> > a0e0ec9f7d (t: provide a perl() function which uses $PERL_PATH,
> > 2013-10-28) so that test writers don't have to remember this.
> > 
> > That said, I wonder if it would be hard to simply do the python bits
> > here in perl. This is the first use of python in our test scripts (and
> 
> Hmm, not quite the _first_ use:
> 
> $ git grep PYTHON_PATH -- t
> t/lib-git-p4.sh:        (cd / && "$PYTHON_PATH" -c 'import time; print(int(time.time()))')
> t/lib-git-p4.sh:        "$PYTHON_PATH" "$TRASH_DIRECTORY/marshal-dump.py"
> t/t9020-remote-svn.sh:export PATH PYTHON_PATH GIT_BUILD_DIR
> t/t9020-remote-svn.sh:exec "$PYTHON_PATH" "$GIT_BUILD_DIR/contrib/svn-fe/svnrdump_sim.py" "$@"
> t/t9802-git-p4-filetype.sh:             "$PYTHON_PATH" "$TRASH_DIRECTORY/k_smush.py" <"$cli/k-text-k" >cli-k-text-k-smush &&
> t/t9802-git-p4-filetype.sh:             "$PYTHON_PATH" "$TRASH_DIRECTORY/ko_smush.py" <"$cli/k-text-ko" >cli-k-text-ko-smush &&
> t/t9802-git-p4-filetype.sh:             "$PYTHON_PATH" "$TRASH_DIRECTORY/gendouble.py" >%double.png &&
> t/t9810-git-p4-rcs.sh:  "$PYTHON_PATH" "$TRASH_DIRECTORY/scrub_k.py" <"$git/$file" >"$scrub" &&
> t/t9810-git-p4-rcs.sh:  "$PYTHON_PATH" "$TRASH_DIRECTORY/scrub_ko.py" <"$git/$file" >"$scrub" &&
> $ 

OK, the first for a feature that is not already written in python
(leading into my second claim that python is used only for fringe
commands ;) ).

Though maybe I am wrong that the remote-svn stuff requires python. I
thought it did, but poking around, it looks like it's all C, and just
the "svnrdump_sim" helper is python.

At any rate, I think the point still stands that perl is our main
scripting language. I'd rather keep us to that unless there's a good
reason not to.

-Peff

Re: [PATCH v7 2/2] json-writer: t0019: add Python unit test

[Jeff King]

On Wed, Jun 06, 2018 at 10:23:53PM -0400, Jeff King wrote:

> Though maybe I am wrong that the remote-svn stuff requires python. I
> thought it did, but poking around, it looks like it's all C, and just
> the "svnrdump_sim" helper is python.

I think I was getting this mixed up with the git_remote_helpers python
work, which was removed long ago in ae34ac126f (git_remote_helpers:
remove little used Python library, 2013-09-07).

Note that it really changes much, but I was curious enough to dig down.

-Peff

Re: [PATCH v7 2/2] json-writer: t0019: add Python unit test

[Ramsay Jones]

On 07/06/18 03:23, Jeff King wrote:
> On Thu, Jun 07, 2018 at 01:16:14AM +0100, Ramsay Jones wrote:
> 
>>> Probably. We may want to go the same route as we did for perl in 
>>> a0e0ec9f7d (t: provide a perl() function which uses $PERL_PATH,
>>> 2013-10-28) so that test writers don't have to remember this.
>>>
>>> That said, I wonder if it would be hard to simply do the python bits
>>> here in perl. This is the first use of python in our test scripts (and
>>
>> Hmm, not quite the _first_ use:
>>
>> $ git grep PYTHON_PATH -- t
>> t/lib-git-p4.sh:        (cd / && "$PYTHON_PATH" -c 'import time; print(int(time.time()))')
>> t/lib-git-p4.sh:        "$PYTHON_PATH" "$TRASH_DIRECTORY/marshal-dump.py"
>> t/t9020-remote-svn.sh:export PATH PYTHON_PATH GIT_BUILD_DIR
>> t/t9020-remote-svn.sh:exec "$PYTHON_PATH" "$GIT_BUILD_DIR/contrib/svn-fe/svnrdump_sim.py" "$@"
>> t/t9802-git-p4-filetype.sh:             "$PYTHON_PATH" "$TRASH_DIRECTORY/k_smush.py" <"$cli/k-text-k" >cli-k-text-k-smush &&
>> t/t9802-git-p4-filetype.sh:             "$PYTHON_PATH" "$TRASH_DIRECTORY/ko_smush.py" <"$cli/k-text-ko" >cli-k-text-ko-smush &&
>> t/t9802-git-p4-filetype.sh:             "$PYTHON_PATH" "$TRASH_DIRECTORY/gendouble.py" >%double.png &&
>> t/t9810-git-p4-rcs.sh:  "$PYTHON_PATH" "$TRASH_DIRECTORY/scrub_k.py" <"$git/$file" >"$scrub" &&
>> t/t9810-git-p4-rcs.sh:  "$PYTHON_PATH" "$TRASH_DIRECTORY/scrub_ko.py" <"$git/$file" >"$scrub" &&
>> $ 
> 
> OK, the first for a feature that is not already written in python
> (leading into my second claim that python is used only for fringe
> commands ;) ).
> 
> Though maybe I am wrong that the remote-svn stuff requires python. I
> thought it did, but poking around, it looks like it's all C, and just
> the "svnrdump_sim" helper is python.

Heh, I was a bit tired last night, so although I knew that
I required python to be installed to run the test-suite, I
could not remember why. As soon as I went to bed, ... :)

I recently installed Ubuntu 18.04, so that I could get a heads
up on any possible problems later this month when I install
Linux Mint 19. In order to get the test-suite to run, I had
to set 'PYTHON_PATH = /usr/bin/python3' in my config.mak file.
(yes, I could have set NO_PYTHON, but you get the idea).

Ubuntu 18.04 no longer installs python2 by default (it has
ported to python3), but presumably you can still install it
as '/usr/bin/python' (I didn't check).

In any event, it was t9020-remote-svn.sh that was failing
which, despite the name, does not depend on 'svn'. As you
already noted, it does run svnrdump_sim.py and the git-remote-testsvn.

> At any rate, I think the point still stands that perl is our main
> scripting language. I'd rather keep us to that unless there's a good
> reason not to.

Agreed. And I see it has come to pass ... :-D

ATB,
Ramsay Jones

Re: [PATCH v7 2/2] json-writer: t0019: add Python unit test

[Jeff Hostetler]

On 6/6/2018 1:10 PM, Todd Zullinger wrote:
> git@jeffhostetler.com wrote:
>> +# As a sanity check, ask Python to parse our generated JSON.  Let Python
>> +# recursively dump the resulting dictionary in sorted order.  Confirm that
>> +# that matches our expectations.
>> +test_expect_success PYTHON 'parse JSON using Python' '
> [...]
>> +	python "$TEST_DIRECTORY"/t0019/parse_json_1.py <output.json >actual &&
> 
> Would this be better using $PYTHON_PATH rather than
> hard-coding python as the command?
> 

good catch!
thanks
Jeff