make git pre-commit hook only test files to be committed

Right now, the git pre-commit hook is pretty annoying to work with when
development since it tests every single file.  That means notes, incomplete
stuff, etc. will be run through the tests.  So all of the files need to be
clean in order to commit even a single trivial fix.  This commit changes it
so that the pre-commit hook is only run on the files staged to be committed.

diff --git a/hooks/pre-commit b/hooks/pre-commit
index 4cc15059e72a97c995b18bc155f4fa0dd6fde465..d33c701815c2e5475a9e5aec8376b62982ba7539 100755 (executable)
--- a/hooks/pre-commit
+++ b/hooks/pre-commit
@@ -1,4 +1,4 @@
-#!/bin/sh
+#!/bin/bash
 #
 # Simple pre-commit hook to check that there are no errors in the fdroidserver
 # source files.
@@ -6,11 +6,45 @@
 # Redirect output to stderr.
 exec 1>&2
 
-PY_FILES="fdroid makebuildserver setup.py examples/*.py buildserver/*.py fdroidserver/*.py"
-PY_TEST_FILES="tests/*.TestCase"
-SH_FILES="hooks/pre-commit"
-BASH_FILES="fd-commit jenkins-build docs/update.sh completion/bash-completion"
-RB_FILES="buildserver/cookbooks/*/recipes/*.rb"
+files=`git diff-index --cached HEAD 2>&1 | sed 's/^:.*     //' | uniq | cut -b100-500`
+if [ -z $files ]; then
+    PY_FILES="fdroid makebuildserver setup.py examples/*.py buildserver/*.py fdroidserver/*.py"
+    PY_TEST_FILES="tests/*.TestCase"
+    SH_FILES="hooks/pre-commit"
+    BASH_FILES="fd-commit jenkins-build docs/update.sh completion/bash-completion"
+    RB_FILES="buildserver/cookbooks/*/recipes/*.rb"
+else
+    # if actually committing right now, then only run on the files
+    # that are going to be committed at this moment
+    PY_FILES=
+    PY_TEST_FILES=
+    SH_FILES=
+    BASH_FILES=
+    RB_FILES=
+
+    for f in $files; do
+        case $f in
+            *.py)
+                PY_FILES+=" $f"
+                ;;
+            *.TestCase)
+                PY_TEST_FILES+=" $f"
+                ;;
+            *.rb)
+                RB_FILES+=" $f"
+                ;;
+            *)
+                if head -1 $f | grep '^#!/bin/sh' > /dev/null 2>&1; then
+                    SH_FILES+=" $f"
+                elif head -1 $f | grep '^#!/bin/bash' > /dev/null 2>&1; then
+                    BASH_FILES+=" $f"
+                elif head -1 $f | grep '^#!.*python' > /dev/null 2>&1; then
+                    PY_FILES+=" $f"
+                fi
+                ;;
+        esac
+    done
+fi
 
 # In the default configuration, the checks E123, E133, E226, E241 and E242 are
 # ignored because they are not rules unanimously accepted
@@ -49,22 +83,27 @@ else
        err "pep8 is not installed!"
 fi
 
-if ! $PYFLAKES $PY_FILES $PY_TEST_FILES; then
+if [ ! -z $PY_FILES $PY_TEST_FILES ]; then
+    if ! $PYFLAKES $PY_FILES $PY_TEST_FILES; then
        err "pyflakes tests failed!"
+    fi
 fi
 
-if ! $PEP8 --ignore=$PEP8_IGNORE $PY_FILES; then
+if [ ! -z $PY_FILES ]; then
+    if ! $PEP8 --ignore=$PEP8_IGNORE $PY_FILES; then
        err "pep8 tests failed!"
+    fi
 fi
 
 # The tests use a little hack in order to cleanly import the fdroidserver
 # package locally like a regular package.  pep8 doesn't see that, so this
 # makes pep8 skip E402 on the test files that need that hack.
-if ! $PEP8 --ignore=$PEP8_IGNORE,E402 $PY_TEST_FILES; then
+if [ ! -z $PY_TEST_FILES ]; then
+    if ! $PEP8 --ignore=$PEP8_IGNORE,E402 $PY_TEST_FILES; then
        err "pep8 tests failed!"
+    fi
 fi
 
-
 for f in $SH_FILES; do
        if ! dash -n $f; then
                err "dash tests failed!"