From 2654eba854ecaeb06b26e40a952403e0dd2b1659 Mon Sep 17 00:00:00 2001
From: Antonino Porcino <nino.porcino@gmail.com>
Date: Sat, 30 Jul 2016 15:46:43 +0200
Subject: [PATCH] implements #175, better rt-scope syntax parsing

---
 src/reactTemplates.js                   | 56 +++++++++++++++++++------
 test/data/scope-reserved-tokens.rt      |  4 ++
 test/data/scope-reserved-tokens.rt.html |  2 +
 test/src/rt.valid.spec.js               |  7 ++--
 4 files changed, 52 insertions(+), 17 deletions(-)
 create mode 100644 test/data/scope-reserved-tokens.rt
 create mode 100644 test/data/scope-reserved-tokens.rt.html

diff --git a/src/reactTemplates.js b/src/reactTemplates.js
index 6772d6fb..3ac44465 100644
--- a/src/reactTemplates.js
+++ b/src/reactTemplates.js
@@ -417,6 +417,35 @@ function convertHtmlToReact(node, context) {
     }
 }
 
+/**
+ * Parses the rt-scope attribute returning an array of parsed sections
+ *
+ * @param {String} scope The scope attribute to parse
+ * @returns {Array} an array of {expression,identifier}
+ * @throws {String} the part of the string that failed to parse
+ */
+function parseScopeSyntax(text) {
+    // in plain english, this regex scans for:
+    //    any character + one or more space + "as" + one or more space + JavaScript identifier +
+    //    zero or more space + semicolon or end of line + zero or more space
+    // it captures "any character" as the scope expression, "JavaScript identifier" as the identifier
+    const regex = RegExp('([\\s\\S]*?)(?: )+as(?: )+([$_a-zA-Z]+[$_a-zA-Z0-9]*)(?: )*(?:;|$)(?: )*', 'g');
+    const res = [];
+    do {
+        const idx = regex.lastIndex;
+        const match = regex.exec(text);
+        if (regex.lastIndex === idx || match === null) {
+            throw text.substr(idx);
+        }
+        if (match.index === regex.lastIndex) {
+            regex.lastIndex++;
+        }
+        res.push({expression: match[1].trim(), identifier: match[2]});
+    } while (regex.lastIndex < text.length);
+
+    return res;
+}
+
 function handleScopeAttribute(node, context, data) {
     data.innerScope = {
         scopeName: '',
@@ -426,25 +455,26 @@ function handleScopeAttribute(node, context, data) {
 
     data.innerScope.outerMapping = _.zipObject(context.boundParams, context.boundParams);
 
-    _(node.attribs[scopeAttr]).split(';').invokeMap('trim').compact().forEach(scopePart => {
-        const scopeSubParts = _(scopePart).split(' as ').invokeMap('trim').value();
-        if (scopeSubParts.length < 2) {
-            throw RTCodeError.build(context, node, `invalid scope part '${scopePart}'`);
-        }
-        const alias = scopeSubParts[1];
-        const value = scopeSubParts[0];
-        validateJS(alias, node, context);
+    let scopes;
+    try {
+        scopes = parseScopeSyntax(node.attribs[scopeAttr]);
+    } catch (scopePart) {
+        throw RTCodeError.build(context, node, `invalid scope part '${scopePart}'`);
+    }
+
+    scopes.forEach(({expression, identifier}) => {
+        validateJS(identifier, node, context);
 
         // this adds both parameters to the list of parameters passed further down
         // the scope chain, as well as variables that are locally bound before any
         // function call, as with the ones we generate for rt-scope.
-        if (!_.includes(context.boundParams, alias)) {
-            context.boundParams.push(alias);
+        if (!_.includes(context.boundParams, identifier)) {
+            context.boundParams.push(identifier);
         }
 
-        data.innerScope.scopeName += _.upperFirst(alias);
-        data.innerScope.innerMapping[alias] = `var ${alias} = ${value};`;
-        validateJS(data.innerScope.innerMapping[alias], node, context);
+        data.innerScope.scopeName += _.upperFirst(identifier);
+        data.innerScope.innerMapping[identifier] = `var ${identifier} = ${expression};`;
+        validateJS(data.innerScope.innerMapping[identifier], node, context);
     });
 }
 
diff --git a/test/data/scope-reserved-tokens.rt b/test/data/scope-reserved-tokens.rt
new file mode 100644
index 00000000..83d0266f
--- /dev/null
+++ b/test/data/scope-reserved-tokens.rt
@@ -0,0 +1,4 @@
+<div rt-scope="'as fast as possible' as message;';' as semicolon;'as' as as">
+	{message}{semicolon}{as}
+</div>
+
diff --git a/test/data/scope-reserved-tokens.rt.html b/test/data/scope-reserved-tokens.rt.html
new file mode 100644
index 00000000..e984be6e
--- /dev/null
+++ b/test/data/scope-reserved-tokens.rt.html
@@ -0,0 +1,2 @@
+<div>as fast as possible;as</div>
+
diff --git a/test/src/rt.valid.spec.js b/test/src/rt.valid.spec.js
index 4f5a4416..123fd492 100644
--- a/test/src/rt.valid.spec.js
+++ b/test/src/rt.valid.spec.js
@@ -170,14 +170,13 @@ module.exports = {
                 'scope-evaluated-after-repeat2.rt',
                 'scope-evaluated-after-if.rt',
                 'scope-obj.rt',
+                'scope-reserved-tokens.rt',
                 'repeat-literal-collection.rt',
                 'include.rt'
             ];
             t.plan(files.length);
 
-            files.forEach(check);
-
-            function check(testFile) {
+            files.forEach(testFile => {
                 const filename = path.join(dataPath, testFile);
                 const options = {
                     readFileSync: fsUtil.createRelativeReadFileSync(filename)
@@ -196,7 +195,7 @@ module.exports = {
                     console.log(testFile, e);
                     fs.writeFileSync(filename + '.code.js', code);
                 }
-            }
+            });
         });
     }
 };