[PATCH v1 0/2] travis-ci: dedicated scripts + skip duplicated builds

[PATCH v1 0/2] travis-ci: dedicated scripts + skip duplicated builds

[larsxschneider]

From: Lars Schneider <larsxschneider@gmail.com>

Hi,

the patches were previously discussed here:
https://public-inbox.org/git/xmqqinifrrzh.fsf@gitster.mtv.corp.google.com/#t

Over there Junio posted the original patch to skip a build on Travis
CI. The patch became 2/2 in this series.

Cheers,
Lars

Base Ref: master
Web-Diff: https://github.com/larsxschneider/git/commit/65ab003ec9
Checkout: git fetch https://github.com/larsxschneider/git travisci/move-into-ci-v1 && git checkout 65ab003ec9

Lars Schneider (2):
  travis-ci: move Travis CI code into dedicated scripts
  travis-ci: skip a branch build if equal tag is present

 .travis.yml                | 88 +++++-----------------------------------------
 ci/install-dependencies.sh | 43 ++++++++++++++++++++++
 ci/lib-travisci.sh         | 28 +++++++++++++++
 ci/print-test-failures.sh  | 18 ++++++++++
 ci/run-build.sh            |  8 +++++
 ci/run-linux32-docker.sh   | 23 ++++++++++++
 ci/run-static-analysis.sh  |  8 +++++
 ci/run-tests.sh            | 10 ++++++
 ci/run-windows-build.sh    |  2 ++
 ci/test-documentation.sh   |  4 ++-
 10 files changed, 151 insertions(+), 81 deletions(-)
 create mode 100755 ci/install-dependencies.sh
 create mode 100755 ci/lib-travisci.sh
 create mode 100755 ci/print-test-failures.sh
 create mode 100755 ci/run-build.sh
 create mode 100755 ci/run-linux32-docker.sh
 create mode 100755 ci/run-static-analysis.sh
 create mode 100755 ci/run-tests.sh


base-commit: 3ec7d702a89c647ddf42a59bc3539361367de9d5
--
2.14.1

[PATCH v1 1/2] travis-ci: move Travis CI code into dedicated scripts

[larsxschneider]

From: Lars Schneider <larsxschneider@gmail.com>

Most of the Travis CI commands are in the '.travis.yml'. The yml format
does not support functions and therefore code duplication is necessary
to run commands across all builds.

To fix this, add a library for common CI functions. Move all Travis CI
code into dedicated scripts and make them call the library first.

Signed-off-by: Lars Schneider <larsxschneider@gmail.com>
---
 .travis.yml                | 88 +++++-----------------------------------------
 ci/install-dependencies.sh | 43 ++++++++++++++++++++++
 ci/lib-travisci.sh         |  5 +++
 ci/print-test-failures.sh  | 18 ++++++++++
 ci/run-build.sh            |  8 +++++
 ci/run-linux32-docker.sh   | 23 ++++++++++++
 ci/run-static-analysis.sh  |  8 +++++
 ci/run-tests.sh            | 10 ++++++
 ci/run-windows-build.sh    |  2 ++
 ci/test-documentation.sh   |  4 ++-
 10 files changed, 128 insertions(+), 81 deletions(-)
 create mode 100755 ci/install-dependencies.sh
 create mode 100755 ci/lib-travisci.sh
 create mode 100755 ci/print-test-failures.sh
 create mode 100755 ci/run-build.sh
 create mode 100755 ci/run-linux32-docker.sh
 create mode 100755 ci/run-static-analysis.sh
 create mode 100755 ci/run-tests.sh

diff --git a/.travis.yml b/.travis.yml
index 278943d14a..fead995edd 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -61,23 +61,8 @@ matrix:
       services:
         - docker
       before_install:
-        - docker pull daald/ubuntu32:xenial
       before_script:
-      script:
-        - >
-          docker run
-          --interactive
-          --env DEVELOPER
-          --env DEFAULT_TEST_TARGET
-          --env GIT_PROVE_OPTS
-          --env GIT_TEST_OPTS
-          --env GIT_TEST_CLONE_2GB
-          --volume "${PWD}:/usr/src/git"
-          daald/ubuntu32:xenial
-          /usr/src/git/ci/run-linux32-build.sh $(id -u $USER)
-        # Use the following command to debug the docker build locally:
-        # $ docker run -itv "${PWD}:/usr/src/git" --entrypoint /bin/bash daald/ubuntu32:xenial
-        # root@container:/# /usr/src/git/ci/run-linux32-build.sh
+      script: ci/run-linux32-docker.sh
     - env: Static Analysis
       os: linux
       compiler:
@@ -86,9 +71,8 @@ matrix:
           packages:
           - coccinelle
       before_install:
-      script:
-        # "before_script" that builds Git is inherited from base job
-        - make coccicheck
+      # "before_script" that builds Git is inherited from base job
+      script: ci/run-static-analysis.sh
       after_failure:
     - env: Documentation
       os: linux
@@ -99,70 +83,14 @@ matrix:
           - asciidoc
           - xmlto
       before_install:
-      before_script: gem install asciidoctor
+      before_script:
       script: ci/test-documentation.sh
       after_failure:
 
-before_install:
-  - >
-    case "${TRAVIS_OS_NAME:-linux}" in
-    linux)
-      export GIT_TEST_HTTPD=YesPlease
-
-      mkdir --parents custom/p4
-      pushd custom/p4
-        wget --quiet http://filehost.perforce.com/perforce/r$LINUX_P4_VERSION/bin.linux26x86_64/p4d
-        wget --quiet http://filehost.perforce.com/perforce/r$LINUX_P4_VERSION/bin.linux26x86_64/p4
-        chmod u+x p4d
-        chmod u+x p4
-        export PATH="$(pwd):$PATH"
-      popd
-      mkdir --parents custom/git-lfs
-      pushd custom/git-lfs
-        wget --quiet https://github.com/github/git-lfs/releases/download/v$LINUX_GIT_LFS_VERSION/git-lfs-linux-amd64-$LINUX_GIT_LFS_VERSION.tar.gz
-        tar --extract --gunzip --file "git-lfs-linux-amd64-$LINUX_GIT_LFS_VERSION.tar.gz"
-        cp git-lfs-$LINUX_GIT_LFS_VERSION/git-lfs .
-        export PATH="$(pwd):$PATH"
-      popd
-      ;;
-    osx)
-      brew update --quiet
-      # Uncomment this if you want to run perf tests:
-      # brew install gnu-time
-      brew install git-lfs gettext
-      brew link --force gettext
-      brew install caskroom/cask/perforce
-      ;;
-    esac;
-    echo "$(tput setaf 6)Perforce Server Version$(tput sgr0)";
-    p4d -V | grep Rev.;
-    echo "$(tput setaf 6)Perforce Client Version$(tput sgr0)";
-    p4 -V | grep Rev.;
-    echo "$(tput setaf 6)Git-LFS Version$(tput sgr0)";
-    git-lfs version;
-
-before_script: make --jobs=2
-
-script:
-  - >
-    mkdir -p $HOME/travis-cache;
-    ln -s $HOME/travis-cache/.prove t/.prove;
-    make --quiet test;
-
-after_failure:
-  - >
-    : '<-- Click here to see detailed test output!                                                        ';
-    for TEST_EXIT in t/test-results/*.exit;
-    do
-      if [ "$(cat "$TEST_EXIT")" != "0" ];
-      then
-        TEST_OUT="${TEST_EXIT%exit}out";
-        echo "------------------------------------------------------------------------";
-        echo "$(tput setaf 1)${TEST_OUT}...$(tput sgr0)";
-        echo "------------------------------------------------------------------------";
-        cat "${TEST_OUT}";
-      fi;
-    done;
+before_install: ci/install-dependencies.sh
+before_script: ci/run-build.sh
+script: ci/run-tests.sh
+after_failure: ci/print-test-failures.sh
 
 notifications:
   email: false
diff --git a/ci/install-dependencies.sh b/ci/install-dependencies.sh
new file mode 100755
index 0000000000..067e6eb702
--- /dev/null
+++ b/ci/install-dependencies.sh
@@ -0,0 +1,43 @@
+#!/usr/bin/env bash
+#
+# Install dependencies required to build and test Git on Linux and macOS
+#
+
+. ${0%/*}/lib-travisci.sh
+
+case "${TRAVIS_OS_NAME:-linux}" in
+	linux)
+		export GIT_TEST_HTTPD=YesPlease
+
+		mkdir --parents custom/p4
+		pushd custom/p4
+			wget --quiet http://filehost.perforce.com/perforce/r$LINUX_P4_VERSION/bin.linux26x86_64/p4d
+			wget --quiet http://filehost.perforce.com/perforce/r$LINUX_P4_VERSION/bin.linux26x86_64/p4
+			chmod u+x p4d
+			chmod u+x p4
+			export PATH="$(pwd):$PATH"
+		popd
+		mkdir --parents custom/git-lfs
+		pushd custom/git-lfs
+			wget --quiet https://github.com/github/git-lfs/releases/download/v$LINUX_GIT_LFS_VERSION/git-lfs-linux-amd64-$LINUX_GIT_LFS_VERSION.tar.gz
+			tar --extract --gunzip --file "git-lfs-linux-amd64-$LINUX_GIT_LFS_VERSION.tar.gz"
+			cp git-lfs-$LINUX_GIT_LFS_VERSION/git-lfs .
+			export PATH="$(pwd):$PATH"
+		popd
+	;;
+	osx)
+		brew update --quiet
+		# Uncomment this if you want to run perf tests:
+		# brew install gnu-time
+		brew install git-lfs gettext
+		brew link --force gettext
+		brew install caskroom/cask/perforce
+	;;
+esac
+
+echo "$(tput setaf 6)Perforce Server Version$(tput sgr0)"
+p4d -V | grep Rev.
+echo "$(tput setaf 6)Perforce Client Version$(tput sgr0)"
+p4 -V | grep Rev.
+echo "$(tput setaf 6)Git-LFS Version$(tput sgr0)"
+git-lfs version
diff --git a/ci/lib-travisci.sh b/ci/lib-travisci.sh
new file mode 100755
index 0000000000..44d6ba2dd2
--- /dev/null
+++ b/ci/lib-travisci.sh
@@ -0,0 +1,5 @@
+# Library of functions shared by all CI scripts
+
+# Set 'exit on error' for all CI scripts to let the caller know that
+# something went wrong
+set -e
diff --git a/ci/print-test-failures.sh b/ci/print-test-failures.sh
new file mode 100755
index 0000000000..8583e61839
--- /dev/null
+++ b/ci/print-test-failures.sh
@@ -0,0 +1,18 @@
+#!/bin/sh
+#
+# Print output of failing tests
+#
+
+. ${0%/*}/lib-travisci.sh
+
+for TEST_EXIT in t/test-results/*.exit
+	do
+		if [ "$(cat "$TEST_EXIT")" != "0" ]
+		then
+			TEST_OUT="${TEST_EXIT%exit}out"
+			echo "------------------------------------------------------------------------"
+			echo "$(tput setaf 1)${TEST_OUT}...$(tput sgr0)"
+			echo "------------------------------------------------------------------------"
+			cat "${TEST_OUT}"
+		fi
+done
diff --git a/ci/run-build.sh b/ci/run-build.sh
new file mode 100755
index 0000000000..4f940d1032
--- /dev/null
+++ b/ci/run-build.sh
@@ -0,0 +1,8 @@
+#!/bin/sh
+#
+# Build Git
+#
+
+. ${0%/*}/lib-travisci.sh
+
+make --jobs=2
diff --git a/ci/run-linux32-docker.sh b/ci/run-linux32-docker.sh
new file mode 100755
index 0000000000..0edf63acfa
--- /dev/null
+++ b/ci/run-linux32-docker.sh
@@ -0,0 +1,23 @@
+#!/bin/sh
+#
+# Download and run Docker image to build and test 32-bit Git
+#
+
+. ${0%/*}/lib-travisci.sh
+
+docker pull daald/ubuntu32:xenial
+
+# Use the following command to debug the docker build locally:
+# $ docker run -itv "${PWD}:/usr/src/git" --entrypoint /bin/bash daald/ubuntu32:xenial
+# root@container:/# /usr/src/git/ci/run-linux32-build.sh
+
+docker run \
+	--interactive \
+	--env DEVELOPER \
+	--env DEFAULT_TEST_TARGET \
+	--env GIT_PROVE_OPTS \
+	--env GIT_TEST_OPTS \
+	--env GIT_TEST_CLONE_2GB \
+	--volume "${PWD}:/usr/src/git" \
+	daald/ubuntu32:xenial \
+	/usr/src/git/ci/run-linux32-build.sh $(id -u $USER)
diff --git a/ci/run-static-analysis.sh b/ci/run-static-analysis.sh
new file mode 100755
index 0000000000..68dd0f080e
--- /dev/null
+++ b/ci/run-static-analysis.sh
@@ -0,0 +1,8 @@
+#!/bin/sh
+#
+# Perform various static code analysis checks
+#
+
+. ${0%/*}/lib-travisci.sh
+
+make coccicheck
diff --git a/ci/run-tests.sh b/ci/run-tests.sh
new file mode 100755
index 0000000000..f0c743de94
--- /dev/null
+++ b/ci/run-tests.sh
@@ -0,0 +1,10 @@
+#!/bin/sh
+#
+# Test Git
+#
+
+. ${0%/*}/lib-travisci.sh
+
+mkdir -p $HOME/travis-cache
+ln -s $HOME/travis-cache/.prove t/.prove
+make --quiet test
diff --git a/ci/run-windows-build.sh b/ci/run-windows-build.sh
index 2d98f6b2f9..8757b3a97c 100755
--- a/ci/run-windows-build.sh
+++ b/ci/run-windows-build.sh
@@ -6,6 +6,8 @@
 # supported) and a commit hash.
 #
 
+. ${0%/*}/lib-travisci.sh
+
 test $# -ne 2 && echo "Unexpected number of parameters" && exit 1
 test -z "$GFW_CI_TOKEN" && echo "GFW_CI_TOKEN not defined" && exit
 
diff --git a/ci/test-documentation.sh b/ci/test-documentation.sh
index 6214e6acb4..7a0a848e83 100755
--- a/ci/test-documentation.sh
+++ b/ci/test-documentation.sh
@@ -3,7 +3,9 @@
 # Perform sanity checks on documentation and build it.
 #
 
-set -e
+. ${0%/*}/lib-travisci.sh
+
+gem install asciidoctor
 
 make check-builtins
 make check-docs
-- 
2.14.1

[PATCH v1 2/2] travis-ci: skip a branch build if equal tag is present

[larsxschneider]

From: Lars Schneider <larsxschneider@gmail.com>

If we push a branch and a tag pointing to the HEAD of this branch,
then Travis CI would run the build twice. This wastes resources and
slows the testing.

Add a function to detect this situation and skip the build the branch
if appropriate. Invoke this function on every build.

Helped-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Lars Schneider <larsxschneider@gmail.com>
---
 ci/lib-travisci.sh | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/ci/lib-travisci.sh b/ci/lib-travisci.sh
index 44d6ba2dd2..9c4ae9bdd0 100755
--- a/ci/lib-travisci.sh
+++ b/ci/lib-travisci.sh
@@ -1,5 +1,28 @@
 # Library of functions shared by all CI scripts
 
+skip_branch_tip_with_tag () {
+	# Sometimes, a branch is pushed at the same time the tag that points
+	# at the same commit as the tip of the branch is pushed, and building
+	# both at the same time is a waste.
+	#
+	# Travis gives a tagname e.g. v2.14.0 in $TRAVIS_BRANCH when
+	# the build is triggered by a push to a tag.  Let's see if
+	# $TRAVIS_BRANCH is exactly at a tag, and if so, if it is
+	# different from $TRAVIS_BRANCH.  That way, we can tell if
+	# we are building the tip of a branch that is tagged and
+	# we can skip the build because we won't be skipping a build
+	# of a tag.
+
+	if TAG=$(git describe --exact-match "$TRAVIS_BRANCH" 2>/dev/null) &&
+		$TAG != $TRAVIS_BRANCH
+	then
+		echo "Tip of $TRAVIS_BRANCH is exactly at $TAG"
+		exit 0
+	fi
+}
+
 # Set 'exit on error' for all CI scripts to let the caller know that
 # something went wrong
 set -e
+
+skip_branch_tip_with_tag
-- 
2.14.1

Re: [PATCH v1 1/2] travis-ci: move Travis CI code into dedicated scripts

[Junio C Hamano]

larsxschneider@gmail.com writes:

> From: Lars Schneider <larsxschneider@gmail.com>
>
> Most of the Travis CI commands are in the '.travis.yml'. The yml format
> does not support functions and therefore code duplication is necessary
> to run commands across all builds.
>
> To fix this, add a library for common CI functions. Move all Travis CI
> code into dedicated scripts and make them call the library first.
>
> Signed-off-by: Lars Schneider <larsxschneider@gmail.com>
> ---

Thanks.  I _think_ you ended up not having to use shell function to
avoid code duplication ;-) but I find the script part of the result
much easier to understand.

Two things I noticed:

 - run-windows-build.sh did not use to run with "set -e" but now it
   does because it includes lib-travisci.sh; if (I didn't check with
   fine toothed comb) the original were not "set -e" clean, we may
   see unwanted errors in run-windows-build.sh, but that is
   sometihng we can fix going forward.

 - it seems that the test output section lost ": <- click here...";
   I do not know if there is a negative consequence of this change.

Indentation of some scripts were a bit too deep and I found it hard
to read them, so the following is what I did (but did not commit)
while reading them through.

Thanks.

 ci/install-dependencies.sh | 51 ++++++++++++++++++++++++----------------------
 ci/print-test-failures.sh  | 18 ++++++++--------
 2 files changed, 36 insertions(+), 33 deletions(-)

diff --git a/ci/install-dependencies.sh b/ci/install-dependencies.sh
index 067e6eb702..a29246af35 100755
--- a/ci/install-dependencies.sh
+++ b/ci/install-dependencies.sh
@@ -5,33 +5,36 @@
 
 . ${0%/*}/lib-travisci.sh
 
+P4WHENCE=http://filehost.perforce.com/perforce/r$LINUX_P4_VERSION
+LFSWHENCE=https://github.com/github/git-lfs/releases/download/v$LINUX_GIT_LFS_VERSION
+
 case "${TRAVIS_OS_NAME:-linux}" in
-	linux)
-		export GIT_TEST_HTTPD=YesPlease
+linux)
+	export GIT_TEST_HTTPD=YesPlease
 
-		mkdir --parents custom/p4
-		pushd custom/p4
-			wget --quiet http://filehost.perforce.com/perforce/r$LINUX_P4_VERSION/bin.linux26x86_64/p4d
-			wget --quiet http://filehost.perforce.com/perforce/r$LINUX_P4_VERSION/bin.linux26x86_64/p4
-			chmod u+x p4d
-			chmod u+x p4
-			export PATH="$(pwd):$PATH"
-		popd
-		mkdir --parents custom/git-lfs
-		pushd custom/git-lfs
-			wget --quiet https://github.com/github/git-lfs/releases/download/v$LINUX_GIT_LFS_VERSION/git-lfs-linux-amd64-$LINUX_GIT_LFS_VERSION.tar.gz
-			tar --extract --gunzip --file "git-lfs-linux-amd64-$LINUX_GIT_LFS_VERSION.tar.gz"
-			cp git-lfs-$LINUX_GIT_LFS_VERSION/git-lfs .
-			export PATH="$(pwd):$PATH"
-		popd
+	mkdir --parents custom/p4
+	pushd custom/p4
+		wget --quiet "$P4WHENCE/bin.linux26x86_64/p4d"
+		wget --quiet "$P4WHENCE/bin.linux26x86_64/p4"
+		chmod u+x p4d
+		chmod u+x p4
+		export PATH="$(pwd):$PATH"
+	popd
+	mkdir --parents custom/git-lfs
+	pushd custom/git-lfs
+		wget --quiet "$LFSWHENCE/git-lfs-linux-amd64-$LINUX_GIT_LFS_VERSION.tar.gz"
+		tar --extract --gunzip --file "git-lfs-linux-amd64-$LINUX_GIT_LFS_VERSION.tar.gz"
+		cp git-lfs-$LINUX_GIT_LFS_VERSION/git-lfs .
+		export PATH="$(pwd):$PATH"
+	popd
 	;;
-	osx)
-		brew update --quiet
-		# Uncomment this if you want to run perf tests:
-		# brew install gnu-time
-		brew install git-lfs gettext
-		brew link --force gettext
-		brew install caskroom/cask/perforce
+osx)
+	brew update --quiet
+	# Uncomment this if you want to run perf tests:
+	# brew install gnu-time
+	brew install git-lfs gettext
+	brew link --force gettext
+	brew install caskroom/cask/perforce
 	;;
 esac
 
diff --git a/ci/print-test-failures.sh b/ci/print-test-failures.sh
index 8583e61839..8c8973cbf3 100755
--- a/ci/print-test-failures.sh
+++ b/ci/print-test-failures.sh
@@ -6,13 +6,13 @@
 . ${0%/*}/lib-travisci.sh
 
 for TEST_EXIT in t/test-results/*.exit
-	do
-		if [ "$(cat "$TEST_EXIT")" != "0" ]
-		then
-			TEST_OUT="${TEST_EXIT%exit}out"
-			echo "------------------------------------------------------------------------"
-			echo "$(tput setaf 1)${TEST_OUT}...$(tput sgr0)"
-			echo "------------------------------------------------------------------------"
-			cat "${TEST_OUT}"
-		fi
+do
+	if [ "$(cat "$TEST_EXIT")" != "0" ]
+	then
+		TEST_OUT="${TEST_EXIT%exit}out"
+		echo "------------------------------------------------------------------------"
+		echo "$(tput setaf 1)${TEST_OUT}...$(tput sgr0)"
+		echo "------------------------------------------------------------------------"
+		cat "${TEST_OUT}"
+	fi
 done

Re: [PATCH v1 2/2] travis-ci: skip a branch build if equal tag is present

[SZEDER Gábor]

> If we push a branch and a tag pointing to the HEAD of this branch,

s/the HEAD of//, perhaps?
There is no such thing as "HEAD" (all capital!) of a branch, is it?

> then Travis CI would run the build twice. This wastes resources and

Nit: s/run the build/build and test the same tree/, to further stress
that the two builds are redundant.

> slows the testing.
> 
> Add a function to detect this situation and skip the build the branch

s/skip the build/skip building/ ?

> if appropriate. Invoke this function on every build.
> 
> Helped-by: Junio C Hamano <gitster@pobox.com>
> Signed-off-by: Lars Schneider <larsxschneider@gmail.com>
> ---
>  ci/lib-travisci.sh | 23 +++++++++++++++++++++++
>  1 file changed, 23 insertions(+)
> 
> diff --git a/ci/lib-travisci.sh b/ci/lib-travisci.sh
> index 44d6ba2dd2..9c4ae9bdd0 100755
> --- a/ci/lib-travisci.sh
> +++ b/ci/lib-travisci.sh
> @@ -1,5 +1,28 @@
>  # Library of functions shared by all CI scripts
>  
> +skip_branch_tip_with_tag () {
> +	# Sometimes, a branch is pushed at the same time the tag that points
> +	# at the same commit as the tip of the branch is pushed, and building
> +	# both at the same time is a waste.
> +	#
> +	# Travis gives a tagname e.g. v2.14.0 in $TRAVIS_BRANCH when
> +	# the build is triggered by a push to a tag.  Let's see if
> +	# $TRAVIS_BRANCH is exactly at a tag, and if so, if it is
> +	# different from $TRAVIS_BRANCH.  That way, we can tell if
> +	# we are building the tip of a branch that is tagged and
> +	# we can skip the build because we won't be skipping a build
> +	# of a tag.
> +
> +	if TAG=$(git describe --exact-match "$TRAVIS_BRANCH" 2>/dev/null) &&
> +		$TAG != $TRAVIS_BRANCH

This must be

    [ $TAG != $TRAVIS_BRANCH ]

otherwise the shell will rightfully complain:

  $ TRAVIS_BRANCH=v2.14.0 ./ci/lib-travisci.sh 
  ./ci/lib-travisci.sh: line 17: v2.14.0: command not found

Furthermore, I would prefer quotes around $TAG and $TRAVIS_BRANCH.  If
either one of those two variables were empty (or contain multiple
words) at that point, the shell would complain.  Now, I don't think
that either can end up being empty, so quotes are not necessary, but
having quotes around them would save future readers from spending
brain cycles on this unnecessarily.

> +	then
> +		echo "Tip of $TRAVIS_BRANCH is exactly at $TAG"
> +		exit 0
> +	fi
> +}
> +
>  # Set 'exit on error' for all CI scripts to let the caller know that
>  # something went wrong
>  set -e
> +
> +skip_branch_tip_with_tag
> -- 
> 2.14.1
> 
> 

Re: [PATCH v1 2/2] travis-ci: skip a branch build if equal tag is present

[Lars Schneider]

> On 11 Sep 2017, at 16:52, SZEDER Gábor <szeder.dev@gmail.com> wrote:
> 
>> If we push a branch and a tag pointing to the HEAD of this branch,
> 
> s/the HEAD of//, perhaps?
> There is no such thing as "HEAD" (all capital!) of a branch, is it?

Agreed, maybe:
"If we push a branch and a tag pointing to the tip of this branch..."

Would that be OK for you?


>> then Travis CI would run the build twice. This wastes resources and
> 
> Nit: s/run the build/build and test the same tree/, to further stress
> that the two builds are redundant.

OK, will fix.


>> slows the testing.
>> 
>> Add a function to detect this situation and skip the build the branch
> 
> s/skip the build/skip building/ ?

OK, will fix.


>> if appropriate. Invoke this function on every build.
>> 
>> Helped-by: Junio C Hamano <gitster@pobox.com>
>> Signed-off-by: Lars Schneider <larsxschneider@gmail.com>
>> ---
>> ci/lib-travisci.sh | 23 +++++++++++++++++++++++
>> 1 file changed, 23 insertions(+)
>> 
>> diff --git a/ci/lib-travisci.sh b/ci/lib-travisci.sh
>> index 44d6ba2dd2..9c4ae9bdd0 100755
>> --- a/ci/lib-travisci.sh
>> +++ b/ci/lib-travisci.sh
>> @@ -1,5 +1,28 @@
>> # Library of functions shared by all CI scripts
>> 
>> +skip_branch_tip_with_tag () {
>> +	# Sometimes, a branch is pushed at the same time the tag that points
>> +	# at the same commit as the tip of the branch is pushed, and building
>> +	# both at the same time is a waste.
>> +	#
>> +	# Travis gives a tagname e.g. v2.14.0 in $TRAVIS_BRANCH when
>> +	# the build is triggered by a push to a tag.  Let's see if
>> +	# $TRAVIS_BRANCH is exactly at a tag, and if so, if it is
>> +	# different from $TRAVIS_BRANCH.  That way, we can tell if
>> +	# we are building the tip of a branch that is tagged and
>> +	# we can skip the build because we won't be skipping a build
>> +	# of a tag.
>> +
>> +	if TAG=$(git describe --exact-match "$TRAVIS_BRANCH" 2>/dev/null) &&
>> +		$TAG != $TRAVIS_BRANCH
> 
> This must be
> 
>    [ $TAG != $TRAVIS_BRANCH ]
> 
> otherwise the shell will rightfully complain:
> 
>  $ TRAVIS_BRANCH=v2.14.0 ./ci/lib-travisci.sh 
>  ./ci/lib-travisci.sh: line 17: v2.14.0: command not found
> 
> Furthermore, I would prefer quotes around $TAG and $TRAVIS_BRANCH.  If
> either one of those two variables were empty (or contain multiple
> words) at that point, the shell would complain.  Now, I don't think
> that either can end up being empty, so quotes are not necessary, but
> having quotes around them would save future readers from spending
> brain cycles on this unnecessarily.

Agreed. I will fix both things!


Thanks for the review,
Lars