fix(HtmlParser): ignore LF immediately following pre, textarea & listing

fixes angular#5630

Closes angular#5688

Author: vicb

modules/angular2/src/compiler/html_parser.ts

@@ -106,7 +106,18 @@ class TreeBuilder {
   }
 
   private _consumeText(token: HtmlToken) {
-    this._addToParent(new HtmlTextAst(token.parts[0], token.sourceSpan));
+    let text = token.parts[0];
+    if (text.length > 0 && text[0] == '\n') {
+      let parent = this._getParentElement();
+      if (isPresent(parent) && parent.children.length == 0 &&
+          getHtmlTagDefinition(parent.name).ignoreFirstLf) {
+        text = text.substring(1);
+      }
+    }
+
+    if (text.length > 0) {
+      this._addToParent(new HtmlTextAst(text, token.sourceSpan));
+    }
   }
 
   private _closeVoidElement(): void {

modules/angular2/src/compiler/html_tags.ts

@@ -279,15 +279,17 @@ export class HtmlTagDefinition {
   public implicitNamespacePrefix: string;
   public contentType: HtmlTagContentType;
   public isVoid: boolean;
+  public ignoreFirstLf: boolean;
 
   constructor({closedByChildren, requiredParents, implicitNamespacePrefix, contentType,
-               closedByParent, isVoid}: {
+               closedByParent, isVoid, ignoreFirstLf}: {
     closedByChildren?: string[],
     closedByParent?: boolean,
     requiredParents?: string[],
     implicitNamespacePrefix?: string,
     contentType?: HtmlTagContentType,
-    isVoid?: boolean
+    isVoid?: boolean,
+    ignoreFirstLf?: boolean
   } = {}) {
     if (isPresent(closedByChildren) && closedByChildren.length > 0) {
       closedByChildren.forEach(tagName => this.closedByChildren[tagName] = true);
@@ -301,6 +303,7 @@ export class HtmlTagDefinition {
     }
     this.implicitNamespacePrefix = implicitNamespacePrefix;
     this.contentType = isPresent(contentType) ? contentType : HtmlTagContentType.PARSABLE_DATA;
+    this.ignoreFirstLf = normalizeBool(ignoreFirstLf);
   }
 
   requireExtraParent(currentParent: string): boolean {
@@ -388,10 +391,13 @@ var TAG_DEFINITIONS: {[key: string]: HtmlTagDefinition} = {
   'rp': new HtmlTagDefinition({closedByChildren: ['rb', 'rt', 'rtc', 'rp'], closedByParent: true}),
   'optgroup': new HtmlTagDefinition({closedByChildren: ['optgroup'], closedByParent: true}),
   'option': new HtmlTagDefinition({closedByChildren: ['option', 'optgroup'], closedByParent: true}),
+  'pre': new HtmlTagDefinition({ignoreFirstLf: true}),
+  'listing': new HtmlTagDefinition({ignoreFirstLf: true}),
   'style': new HtmlTagDefinition({contentType: HtmlTagContentType.RAW_TEXT}),
   'script': new HtmlTagDefinition({contentType: HtmlTagContentType.RAW_TEXT}),
   'title': new HtmlTagDefinition({contentType: HtmlTagContentType.ESCAPABLE_RAW_TEXT}),
-  'textarea': new HtmlTagDefinition({contentType: HtmlTagContentType.ESCAPABLE_RAW_TEXT}),
+  'textarea': new HtmlTagDefinition(
+      {contentType: HtmlTagContentType.ESCAPABLE_RAW_TEXT, ignoreFirstLf: true}),
 };
 
 var DEFAULT_TAG_DEFINITION = new HtmlTagDefinition();

modules/angular2/test/compiler/html_parser_spec.ts

@@ -178,6 +178,22 @@ export function main() {
           expect(humanizeDom(parser.parse('<math />', 'TestComp')))
               .toEqual([[HtmlElementAst, '@math:math', 0]]);
         });
+
+        it('should ignore LF immediately after textarea, pre and listing', () => {
+          expect(humanizeDom(parser.parse(
+                     '<p>\n</p><textarea>\n</textarea><pre>\n\n</pre><listing>\n\n</listing>',
+                     'TestComp')))
+              .toEqual([
+                [HtmlElementAst, 'p', 0],
+                [HtmlTextAst, '\n', 1],
+                [HtmlElementAst, 'textarea', 0],
+                [HtmlElementAst, 'pre', 0],
+                [HtmlTextAst, '\n', 1],
+                [HtmlElementAst, 'listing', 0],
+                [HtmlTextAst, '\n', 1],
+              ]);
+        });
+
       });
 
       describe('attributes', () => {