[soy mode] Support single-quoted strings in tags

mode/soy/soy.js

@@ -90,6 +90,7 @@
           variables: null,
           scopes: null,
           indent: 0,
+          quoteKind: null,
           localStates: [{
             mode: modes.html,
             state: CodeMirror.startState(modes.html)
@@ -107,6 +108,7 @@
           variables: state.variables,
           scopes: state.scopes,
           indent: state.indent, // Indentation of the following line.
+          quoteKind: state.quoteKind,
           localStates: state.localStates.map(function(localState) {
             return {
               mode: localState.mode,
@@ -211,8 +213,9 @@
                 });
               }
               return "attribute";
-            } else if (stream.match(/^"/)) {
+            } else if (match = stream.match(/^["']/)) {
               state.soyState.push("string");
+              state.quoteKind = match;
               return "string";
             }
             if (match = stream.match(/^\$([\w]+)/)) {
@@ -233,10 +236,11 @@
             return tokenUntil(stream, state, /\{\/literal}/);
 
           case "string":
-            var match = stream.match(/^.*?("|\\[\s\S])/);
+            var match = stream.match(/^.*?(["']|\\[\s\S])/);
             if (!match) {
               stream.skipToEnd();
-            } else if (match[1] == "\"") {
+            } else if (match[1] == state.quoteKind) {
+              state.quoteKind = null;
               state.soyState.pop();
             }
             return "string";

mode/soy/test.js

@@ -101,4 +101,8 @@
      '  [keyword {/if}]',
      '[keyword {/template}]',
      '');
+
+  MT('single-quote-strings',
+     '[keyword {][string "foo"] [string \'bar\'][keyword }]',
+     '');
 })();