FIX: some changes in composer affect all visible text editors

app/assets/javascripts/discourse/components/d-editor.js.es6

@@ -246,15 +246,19 @@ export default Ember.Component.extend({
       }
     });
 
-    this.appEvents.on('composer:insert-text', text => this._addText(this._getSelected(), text));
+    if (this.get('composerEvents')) {
-    this.appEvents.on('composer:replace-text', (oldVal, newVal) => this._replaceText(oldVal, newVal));
+      this.appEvents.on('composer:insert-text', text => this._addText(this._getSelected(), text));
+      this.appEvents.on('composer:replace-text', (oldVal, newVal) => this._replaceText(oldVal, newVal));
+    }
     this._mouseTrap = mouseTrap;
   },
 
   @on('willDestroyElement')
   _shutDown() {
-    this.appEvents.off('composer:insert-text');
+    if (this.get('composerEvents')) {
-    this.appEvents.off('composer:replace-text');
+      this.appEvents.off('composer:insert-text');
+      this.appEvents.off('composer:replace-text');
+    }
 
     const mouseTrap = this._mouseTrap;
     Object.keys(this.get('toolbar.shortcuts')).forEach(sc => mouseTrap.unbind(sc));

app/assets/javascripts/discourse/templates/components/composer-editor.hbs

@@ -10,7 +10,8 @@
            togglePreview="togglePreview"
            validation=validation
            loading=composer.loading
-           forcePreview=forcePreview}}
+           forcePreview=forcePreview
+           composerEvents=true}}
 
 <div class="composer-bottom-right">
   {{#if site.mobileView}}

test/javascripts/components/d-editor-test.js.es6

@@ -62,6 +62,19 @@ function testCase(title, testFunc) {
   });
 }
 
+function composerTestCase(title, testFunc) {
+  componentTest(title, {
+    template: '{{d-editor value=value composerEvents=true}}',
+    setup() {
+      this.set('value', 'hello world.');
+    },
+    test(assert) {
+      const textarea = jumpEnd(this.$('textarea.d-editor-input')[0]);
+      testFunc.call(this, assert, textarea);
+    }
+  });
+}
+
 testCase(`selecting the space before a word`, function(assert, textarea) {
   textarea.selectionStart = 5;
   textarea.selectionEnd = 7;
@@ -760,8 +773,19 @@ componentTest('emoji', {
   }
 });
 
-testCase("replace-text event", function(assert) {
+testCase("replace-text event by default", function(assert) {
+  this.set('value', "red green blue");
 
+  andThen(() => {
+    this.container.lookup('app-events:main').trigger('composer:replace-text', 'green', 'yellow');
+  });
+
+  andThen(() => {
+    assert.equal(this.get('value'), 'red green blue');
+  });
+});
+
+composerTestCase("replace-text event for composer", function(assert) {
   this.set('value', "red green blue");
 
   andThen(() => {
@@ -773,6 +797,7 @@ testCase("replace-text event", function(assert) {
   });
 });
 
+
 (() => {
   // Tests to check cursor/selection after replace-text event.
   const BEFORE = 'red green blue';
@@ -849,7 +874,7 @@ testCase("replace-text event", function(assert) {
 
   for (let i = 0; i < CASES.length; i++) {
     const CASE = CASES[i];
-    testCase(`replace-text event: ${CASE.description}`, function(assert, textarea) {
+    composerTestCase(`replace-text event: ${CASE.description}`, function(assert, textarea) {
       this.set('value', BEFORE);
       setSelection(textarea, CASE.before);
       andThen(() => {