fix(@angular-devkit/schematics): fix generate mangling files contai…

packages/angular_devkit/schematics/src/tree/recorder.ts

@@ -30,9 +30,9 @@ export class UpdateRecorderBase implements UpdateRecorder {
     if (c0 == 0xEF && c1 == 0xBB && c2 == 0xBF) {
       return new UpdateRecorderBom(entry);
     } else if (c0 === 0xFF && c1 == 0xFE) {
-      return new UpdateRecorderBom(entry, 2);
+      return new UpdateRecorderBom(entry);
     } else if (c0 === 0xFE && c1 == 0xFF) {
-      return new UpdateRecorderBom(entry, 2);
+      return new UpdateRecorderBom(entry);
     }
 
     return new UpdateRecorderBase(entry);
@@ -70,7 +70,7 @@ export class UpdateRecorderBase implements UpdateRecorder {
 
 
 export class UpdateRecorderBom extends UpdateRecorderBase {
-  constructor(entry: FileEntry, private _delta = 3) {
+  constructor(entry: FileEntry, private _delta = 1) {
     super(entry);
   }
 

packages/angular_devkit/schematics/src/utility/update-buffer.ts

@@ -201,19 +201,31 @@ export class UpdateBuffer {
   }
 
   protected _slice(start: number): [Chunk, Chunk] {
-    this._assertIndex(start);
+    // If start is longer than the content, use start, otherwise determine exact position in string.
+    const index = start >= this._originalContent.length ? start : this._getTextPosition(start);
+
+    this._assertIndex(index);
 
     // Find the chunk by going through the list.
-    const h = this._linkedList.find(chunk => start <= chunk.end);
+    const h = this._linkedList.find(chunk => index <= chunk.end);
     if (!h) {
       throw Error('Chunk cannot be found.');
     }
 
-    if (start == h.end && h.next !== null) {
+    if (index == h.end && h.next !== null) {
       return [h, h.next];
     }
 
-    return [h, h.slice(start)];
+    return [h, h.slice(index)];
+  }
+
+  /**
+   * Gets the position in the content based on the position in the string.
+   * Some characters might be wider than one byte, thus we have to determine the position using
+   * string functions.
+   */
+  protected _getTextPosition(index: number): number {
+    return Buffer.from(this._originalContent.toString().substring(0, index)).length;
   }
 
   get length(): number {

packages/angular_devkit/schematics/src/utility/update-buffer_spec.ts

@@ -58,6 +58,16 @@ describe('UpdateBuffer', () => {
       mb.insertLeft(6, Buffer.from('Awesome '));
       expect(mb.toString()).toBe('Hello Great Awesome Beautiful World');
     });
+
+    it('works with special characters', () => {
+      const mb = new UpdateBuffer(Buffer.from('Ülaut'));
+
+      mb.insertLeft(1, Buffer.from('m'));
+      expect(mb.toString()).toBe('Ümlaut');
+
+      mb.insertLeft(0, Buffer.from('Hello '));
+      expect(mb.toString()).toBe('Hello Ümlaut');
+    });
   });
 
   describe('delete', () => {