fix(generator): Write URI in sorted order to prevent SHA churn

Author: mhevery

lib/tools/template_cache_generator.dart

@@ -89,11 +89,13 @@ printTemplateCache(Map<String, String> templateKeyMap,
   outSink.write(fileHeader(outputLibrary));
 
   List<Future> reads = <Future>[];
-  templateKeyMap.forEach((uri, templateFile) {
+  templateKeyMap.keys.toList()..sort()..forEach((uri) {
+    var templateFile = templateKeyMap[uri];
     reads.add(new File(templateFile).readAsString().then((fileStr) {
       fileStr = fileStr.replaceAll('"""', r'\"\"\"');
       String resultUri = uri;
-      urlRewriters.forEach((regexp, replacement) {
+      urlRewriters.keys.toList()..sort()..forEach((regexp) {
+        var replacement = urlRewriters[regexp];
         resultUri = resultUri.replaceFirst(regexp, replacement);
       });
       outSink.write(
@@ -139,7 +141,7 @@ class TemplateCollectingVisitor {
         var srcDirUri = new Uri.file(srcPath);
         Source currentSrcDir = sourceCrawler.context.sourceFactory
             .resolveUri2(null, srcDirUri);
-        cacheUris.forEach((uri) => storeUriAsset(uri, currentSrcDir));
+        cacheUris..sort()..forEach((uri) => storeUriAsset(uri, currentSrcDir));
       }
     });
   }
@@ -172,7 +174,8 @@ class TemplateCollectingVisitor {
         var paramName = namedArg.name.label.name;
         if (paramName == 'preCacheUrls') {
           assertList(namedArg.expression).elements
-            .forEach((expression) =>
+            ..sort()
+            ..forEach((expression) =>
                 cacheUris.add(assertString(expression).stringValue));
         }
         if (paramName == 'cache') {

test/io/template_cache_generator_spec.dart

@@ -59,8 +59,8 @@ main() => describe('template_cache_generator', () {
       '\n'
       'primeTemplateCache(TemplateCache tc) {\n'
       'tc.put("rewritten/cssUrls/one.css", new HttpResponse(200, r"""body {}"""));\n'
-      'tc.put("rewritten/cssUrls/two.css", new HttpResponse(200, r"""body {}"""));\n'
       'tc.put("rewritten/cssUrls/three.css", new HttpResponse(200, r"""body {}"""));\n'
+      'tc.put("rewritten/cssUrls/two.css", new HttpResponse(200, r"""body {}"""));\n'
       '}');
     }).whenComplete(() {
       //tmpDir.deleteSync(recursive: true);