From 2294281b32ed844ca75aaf5a2611d6fcd55e4100 Mon Sep 17 00:00:00 2001
From: Billy Kong <billyklh@gmail.com>
Date: Wed, 22 Apr 2020 20:42:00 +0800
Subject: [PATCH] doc and test for options.matcher

---
 readme.md                             | 16 ++++++++++++----
 simple_templating_engine.js           |  5 +----
 test/simple_templating_engine_test.js | 13 ++++++++++++-
 3 files changed, 25 insertions(+), 9 deletions(-)

diff --git a/readme.md b/readme.md
index 9a1e368..0768b27 100644
--- a/readme.md
+++ b/readme.md
@@ -10,14 +10,12 @@
 ```JavaScript
 var templeteEngine = require('./simple_templating_engine.js');
 var template = "Hello, <% change_me %>";
-
-
 var handlerWorld = function(key) { return { '<% change_me %>': 'World' } };
+
 templeteEngine.populate(template, handlerWorld).then(populated => {
     console.log(populated); // "Hello, World"
 });
 
-
 var handlerAsyncWorld = function(key) { return { '<% change_me %>': 'Async World' } };
 (async function() {
   let populated = await templeteEngine.populate(template, handlerAsyncWorld);
@@ -29,7 +27,6 @@ var handlerAsyncWorld = function(key) { return { '<% change_me %>': 'Async World
 It also work with JSON template:
 ```JavaScript
 var templateJSON = `{ "root": <% change_me %> }`;
-
 var handlerJSON = function(key) { 
   return { 
     '<% change_me %>': { 
@@ -59,3 +56,14 @@ templeteEngine.populate(templateJSON, handlerJSON).then(populated => {
     console.log(populated); 
 });
 ```
+
+You can also use another matcher pattern other than `<% ... %>`:
+```JavaScript
+var template = "Hello, {_ change_me _}";
+var options = { matcher: /"{_([^%>]+)?_}"/g}
+var handler = function(key) { return { '{_ change_me _}': 'World' } };
+
+templeteEngine.populate(template, handler, options).then(populated => {
+    console.log(populated); // "Hello, World"
+});
+```
diff --git a/simple_templating_engine.js b/simple_templating_engine.js
index e67c6ce..22481e6 100644
--- a/simple_templating_engine.js
+++ b/simple_templating_engine.js
@@ -10,7 +10,7 @@ function parse(template, options={}) {
   let re = options.matcher || /"<%([^%>]+)?%>"/g;
   let match;
   while(match = re.exec(template)) {
-    keys.push(match[0]);
+    keys.push(match[0]); // this line is never executed
   }
   return [template, keys];
 };
@@ -23,8 +23,6 @@ function merge(template, data, options={}) {
   // console.log(data)
   console.log("\nPopulating...")
   Object.keys(data).forEach(key => {
-    let re = options.matcher || /"<%([^%>]+)?%>"/g;
-    let match;
     while(template.includes(key)) {
       if (typeof data[key] === 'string') {
         console.log(`- mapping ${key} to ${data[key]}`);
@@ -33,7 +31,6 @@ function merge(template, data, options={}) {
         console.log(`- mapping ${key} to ${JSON.stringify(data[key])}`);
         template = template.replace(key, JSON.stringify(data[key]));
       }
-      
     }
   });
   console.log("\nFinishing...");
diff --git a/test/simple_templating_engine_test.js b/test/simple_templating_engine_test.js
index f33d944..804c6d7 100644
--- a/test/simple_templating_engine_test.js
+++ b/test/simple_templating_engine_test.js
@@ -55,8 +55,19 @@ describe('templateEngine#populate()', function() {
       let populated = await templeteEngine.populate(template, handler);
       assert(_.isEqual(JSON.parse(populated), { root: { key1: 'value1', key2: 'value2' }}));
     });
+  });
 
+  context('with custom matcher regex in options', function() {
+    let template, options, handler;
+    beforeEach(function() {
+      template = "Hello, {_ change_me _}";
+      options = { matcher: /"{_([^%>]+)?_}"/g}
+      handler = function(key) { return { '{_ change_me _}': 'World' } }
+    });
 
+    it('should replace the placeholder with the async handler', async function() {
+      let populated = await templeteEngine.populate(template, handler, options);
+      assert.equal(populated, 'Hello, World');
+    });
   });
-
 });
\ No newline at end of file