fix(aio): left align code in aio-code components

aio/src/app/embedded/code/code.component.spec.ts

@@ -105,6 +105,14 @@ describe('CodeComponent', () => {
     expect(lis.length).toBe(0, 'should be no linenums');
   });
 
+  it('should remove common indentation from the code before rendering', () => {
+    hostComponent.linenums = false;
+    hostComponent.code = '  abc\n   def\n  ghi\n\n  jkl\n';
+    fixture.detectChanges();
+    const codeContent = codeComponentDe.nativeElement.querySelector('code').innerText;
+    expect(codeContent).toEqual('abc\n def\nghi\n\njkl');
+  });
+
   it('should trim whitespace from the code before rendering', () => {
     hostComponent.linenums = false;
     hostComponent.code = '\n\n\n' + multiLineCode + '\n\n\n';

aio/src/app/embedded/code/code.component.ts

@@ -70,7 +70,7 @@ export class CodeComponent implements OnChanges {
     private logger: Logger) {}
 
   ngOnChanges() {
-    this.code = this.code && this.code.trim();
+    this.code = this.code && leftAlign(this.code);
 
     if (!this.code) {
       this.setCodeHtml('<p class="code-missing">The code sample is missing.</p>');
@@ -118,3 +118,15 @@ export class CodeComponent implements OnChanges {
       (this.code.match(/\n/g) || []).length > 1 : linenums;
   }
 }
+
+function leftAlign(text) {
+  let indent = Number.MAX_VALUE;
+  const lines = text.split('\n');
+  lines.forEach(line => {
+    const lineIndent = line.search(/\S/);
+    if (lineIndent !== -1) {
+      indent = Math.min(lineIndent, indent);
+    }
+  });
+  return lines.map(line => line.substr(indent)).join('\n').trim();
+}