From: Andrew Moore <amoore@cpan.org>
Date: Fri, 19 Dec 2008 18:31:10 +0000 (+0000)
Subject: Prevent Schema::Loader from overwriting unchanged schema files
X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=commitdiff_plain;h=fb01c1803bc2b4593b8cbac65bca897eabbee3de;p=dbsrgits%2FDBIx-Class-Schema-Loader.git

Prevent Schema::Loader from overwriting unchanged schema files

previously, the make_schema_at feature of Schema::Loader would overwrite
files in the dump_to_dir regardless of whether the underlying database
schema had changed or not. This patch causes Schema::Loader to check
the contents of the current file with the newly created schema from the
database. The file is only overwritten if the two differ. This means
that the old timestamp and creation date are preserved.
---

diff --git a/lib/DBIx/Class/Schema/Loader/Base.pm b/lib/DBIx/Class/Schema/Loader/Base.pm
index fada2be..6e3ca7b 100644
--- a/lib/DBIx/Class/Schema/Loader/Base.pm
+++ b/lib/DBIx/Class/Schema/Loader/Base.pm
@@ -502,6 +502,13 @@ sub _write_classfile {
 
     my $custom_content = $self->_get_custom_content($class, $filename);
 
+    # only re-write the file if new content ($text) is different from old ($custom_content)
+    if ( $custom_content ) {
+        my $no_timestamp = $custom_content;
+        $no_timestamp =~ s/^# Created by DBIx::Class::Schema::Loader.*//;
+        return if ($no_timestamp eq $text);
+    }
+
     $custom_content ||= qq|\n\n# You can replace this text with custom|
         . qq| content, and it will be preserved on regeneration|
         . qq|\n1;\n|;
diff --git a/t/23dumpmore.t b/t/23dumpmore.t
index b3b3d14..94b03e6 100644
--- a/t/23dumpmore.t
+++ b/t/23dumpmore.t
@@ -7,7 +7,7 @@ require DBIx::Class::Schema::Loader;
 
 $^O eq 'MSWin32'
     ? plan(skip_all => "ActiveState perl produces additional warnings, and this test uses unix paths")
-    : plan(tests => 82);
+    : plan(tests => 91);
 
 my $DUMP_PATH = './t/_dump';
 
@@ -52,6 +52,34 @@ sub do_dump_test {
         my $src_file = $schema_path . '/' . $src . '.pm';
         dump_file_not_like($src_file, @{$file_neg_regexes->{$src}});
     }
+
+    my $current_md5sums = {}; # keep track of the md5sums we make so we can return them.
+    my $file_md5sum_equals = $tdata{md5sum_equals} || {};
+    foreach my $src (keys %$file_md5sum_equals) {
+        my $src_file;
+        if ($src eq 'schema' ) {
+            $src_file = $schema_path . '.pm';
+        } else {
+            $src_file = $schema_path . '/' . $src . '.pm';
+        }
+        my $current_md5sum = get_md5sum_from_dump_file($src_file);
+        is( $current_md5sum, $file_md5sum_equals->{$src}, "found the same md5sum ($current_md5sum) for file $src_file" );
+        $current_md5sums->{$src} = $current_md5sum;
+    }
+
+    my $file_md5sum_ne = $tdata{md5sum_ne} || {};
+    foreach my $src (keys %$file_md5sum_ne) {
+        my $src_file;
+        if ($src eq 'schema' ) {
+            $src_file = $schema_path . '.pm';
+        } else {
+            $src_file = $schema_path . '/' . $src . '.pm';
+        }
+        my $current_md5sum = get_md5sum_from_dump_file($src_file);
+        isnt( $current_md5sum, $file_md5sum_equals->{$src}, "found different md5sum ($current_md5sum) for file $src_file" );
+        $current_md5sums->{$src} = $current_md5sum;
+    }
+    return { md5sums => $current_md5sums };
 }
 
 sub dump_file_like {
@@ -79,9 +107,20 @@ sub append_to_class {
     close($appendfh);
 }
 
+sub get_md5sum_from_dump_file {
+    my $path = shift;
+    open(my $dumpfh, '<', $path) or die "Failed to open '$path': $!";
+    my $contents = do { local $/; <$dumpfh>; };
+    close($dumpfh);
+    if ( $contents =~ /md5sum:([^\s]+)/ ) {
+        return $1;
+    }
+    return;
+}
+
 rmtree($DUMP_PATH, 1, 1);
 
-do_dump_test(
+my $dumped = do_dump_test(
     classname => 'DBICTest::DumpMore::1',
     options => { },
     error => '',
@@ -105,11 +144,16 @@ do_dump_test(
             qr/1;\n$/,
         ],
     },
+    md5sum_ne => {
+                  schema => '',
+                  Foo    => '',
+                  Bar    => '',
+              },
 );
 
 append_to_class('DBICTest::DumpMore::1::Foo',q{# XXX This is my custom content XXX});
 
-do_dump_test(
+$dumped = do_dump_test(
     classname => 'DBICTest::DumpMore::1',
     options => { },
     error => '',
@@ -133,9 +177,10 @@ do_dump_test(
             qr/1;\n$/,
         ],
     },
+    md5sum_equals => $dumped->{'md5sums'},
 );
 
-do_dump_test(
+$dumped = do_dump_test(
     classname => 'DBICTest::DumpMore::1',
     options => { really_erase_my_files => 1 },
     error => '',
@@ -167,6 +212,7 @@ do_dump_test(
             qr/# XXX This is my custom content XXX/,
         ],
     },
+    md5sum_ne => $dumped->{'md5sums'},
 );
 
 do_dump_test(