Merge pull request #132 from xxfelixxx/patch-2

Add pre-commit hook and script to check that ccd_defs.json compiles

README.md

@@ -120,5 +120,18 @@ This problem is easily remedied. We need to know CCD size in the camera. We'll g
 So, we'll add the following line to our ccd_defs.json:
 
      "SONY DSC-HX5V": 6.104,
-     
+
+To check that ccd_defs.json compiles, run ccd_defs_check.pl
+If it prints the message 'CCD_DEFS compiles OK', then you can commit your changes.
+
 And so others can use it, we'll do a pull request to add it to our array for everyone else.
+
+---
+
+Maintainers can run the ccd_defs.json compilation test automatically by creating a
+symbolic link in .git/hooks to hooks/pre-commit
+
+     cd .git/hooks
+     ln -s ../../hooks/pre-commit
+
+If ccd_defs.json does not compile, then the pre-commit hook will abort the commit.

ccd_defs_check.pl

@@ -0,0 +1,20 @@
+#!/usr/bin/env perl
+
+use strict;
+
+use File::Basename qw( dirname );
+use File::Spec;
+use JSON;
+
+my $dir = dirname($0);
+my $ccd_defs = File::Spec->catfile($dir, 'ccd_defs.json');
+
+open my $fh, $ccd_defs
+    or die "Unable to open $ccd_defs : $!";
+local $/;
+my $json = <$fh>; # Slurp
+close $fh;
+
+decode_json($json);
+print "CCD_DEFS compiles OK\n";
+exit 0;

hooks/pre-commit

@@ -0,0 +1,22 @@
+#!/bin/sh
+#
+# An example hook script to verify what is about to be committed.
+# Called by "git commit" with no arguments.  The hook should
+# exit with non-zero status after issuing an appropriate message if
+# it wants to stop the commit.
+#
+# To enable this hook, rename this file to "pre-commit".
+
+exec 1>&2
+
+echo "RUNNING PRE-COMMIT"
+
+# Get list of files about to be committed
+if git diff --cached --name-only --diff-filter=ACM | grep 'ccd_defs.json'; then
+    echo "We changed ccd_defs.json"
+    GIT_ROOT=$(git rev-parse --show-toplevel)
+    perl $GIT_ROOT/ccd_defs_check.pl
+fi
+
+# non-zero exit fails the commit
+exit 0