angular-cn/packages/compiler/test/output/abstract_emitter_node_only_spec.ts

/**
 * @license
 * Copyright Google Inc. All Rights Reserved.
 *
 * Use of this source code is governed by an MIT-style license that can be
 * found in the LICENSE file at https://angular.io/license
 */

import {ParseLocation, ParseSourceFile, ParseSourceSpan} from '@angular/compiler';
import {EmitterVisitorContext} from '@angular/compiler/src/output/abstract_emitter';
import {SourceMap} from '@angular/compiler/src/output/source_map';

const SourceMapConsumer = require('source-map').SourceMapConsumer;
const b64 = require('base64-js');


export function main() {
  describe('AbstractEmitter', () => {
    describe('EmitterVisitorContext', () => {
      const fileA = new ParseSourceFile('a0a1a2a3a4a5a6a7a8a9', 'a.js');
      const fileB = new ParseSourceFile('b0b1b2b3b4b5b6b7b8b9', 'b.js');
      let ctx: EmitterVisitorContext;

      beforeEach(() => { ctx = EmitterVisitorContext.createRoot([]); });

      it('should add source files to the source map', () => {
        ctx.print(createSourceSpan(fileA, 0), 'o0');
        ctx.print(createSourceSpan(fileA, 1), 'o1');
        ctx.print(createSourceSpan(fileB, 0), 'o2');
        ctx.print(createSourceSpan(fileB, 1), 'o3');
        const sm = ctx.toSourceMapGenerator('o.js').toJSON();
        expect(sm.sources).toEqual([fileA.url, fileB.url]);
        expect(sm.sourcesContent).toEqual([fileA.content, fileB.content]);
      });

      it('should generate a valid mapping', () => {
        ctx.print(createSourceSpan(fileA, 0), 'fileA-0');
        ctx.println(createSourceSpan(fileB, 1), 'fileB-1');
        ctx.print(createSourceSpan(fileA, 2), 'fileA-2');

        expectMap(ctx, 0, 0, 'a.js', 0, 0);
        expectMap(ctx, 0, 7, 'b.js', 0, 2);
        expectMap(ctx, 1, 0, 'a.js', 0, 4);
      });

      it('should be able to shift the content', () => {
        ctx.print(createSourceSpan(fileA, 0), 'fileA-0');

        const sm = ctx.toSourceMapGenerator(null, 10).toJSON();
        const smc = new SourceMapConsumer(sm);
        expect(smc.originalPositionFor({line: 11, column: 0})).toEqual({
          line: 1,
          column: 0,
          source: 'a.js',
          name: null,
        });
      });

      it('should not map leading segment without span', () => {
        ctx.print(null, '....');
        ctx.print(createSourceSpan(fileA, 0), 'fileA-0');

        expectMap(ctx, 0, 0);
        expectMap(ctx, 0, 4, 'a.js', 0, 0);
        expect(nbSegmentsPerLine(ctx)).toEqual([1]);
      });

      it('should handle indent', () => {
        ctx.incIndent();
        ctx.println(createSourceSpan(fileA, 0), 'fileA-0');
        ctx.incIndent();
        ctx.println(createSourceSpan(fileA, 1), 'fileA-1');
        ctx.decIndent();
        ctx.println(createSourceSpan(fileA, 2), 'fileA-2');

        expectMap(ctx, 0, 0);
        expectMap(ctx, 0, 2, 'a.js', 0, 0);
        expectMap(ctx, 1, 0);
        expectMap(ctx, 1, 2);
        expectMap(ctx, 1, 4, 'a.js', 0, 2);
        expectMap(ctx, 2, 0);
        expectMap(ctx, 2, 2, 'a.js', 0, 4);

        expect(nbSegmentsPerLine(ctx)).toEqual([1, 1, 1]);
      });

      it('should coalesce identical span', () => {
        const span = createSourceSpan(fileA, 0);
        ctx.print(span, 'fileA-0');
        ctx.print(null, '...');
        ctx.print(span, 'fileA-0');
        ctx.print(createSourceSpan(fileB, 0), 'fileB-0');

        expectMap(ctx, 0, 0, 'a.js', 0, 0);
        expectMap(ctx, 0, 7, 'a.js', 0, 0);
        expectMap(ctx, 0, 10, 'a.js', 0, 0);
        expectMap(ctx, 0, 17, 'b.js', 0, 0);

        expect(nbSegmentsPerLine(ctx)).toEqual([2]);
      });
    });
  });
}


// All lines / columns indexes are 0-based
// Note: source-map line indexes are 1-based, column 0-based
function expectMap(
    ctx: EmitterVisitorContext, genLine: number, genCol: number, source: string = null,
    srcLine: number = null, srcCol: number = null) {
  const sm = ctx.toSourceMapGenerator().toJSON();
  const smc = new SourceMapConsumer(sm);
  const genPosition = {line: genLine + 1, column: genCol};
  const origPosition = smc.originalPositionFor(genPosition);
  expect(origPosition.source).toEqual(source);
  expect(origPosition.line).toEqual(srcLine === null ? null : srcLine + 1);
  expect(origPosition.column).toEqual(srcCol);
}

// returns the number of segments per line
function nbSegmentsPerLine(ctx: EmitterVisitorContext) {
  const sm = ctx.toSourceMapGenerator().toJSON();
  const lines = sm.mappings.split(';');
  return lines.map(l => {
    const m = l.match(/,/g);
    return m === null ? 1 : m.length + 1;
  });
}

function createSourceSpan(file: ParseSourceFile, idx: number) {
  const col = 2 * idx;
  const start = new ParseLocation(file, col, 0, col);
  const end = new ParseLocation(file, col + 2, 0, col + 2);
  const sourceSpan = new ParseSourceSpan(start, end);
  return {sourceSpan};
}

export function extractSourceMap(source: string): SourceMap {
  let idx = source.lastIndexOf('\n//#');
  if (idx == -1) return null;
  const smComment = source.slice(idx).trim();
  const smB64 = smComment.split('sourceMappingURL=data:application/json;base64,')[1];
  return smB64 ? JSON.parse(decodeB64String(smB64)) : null;
}

function decodeB64String(s: string): string {
  return b64.toByteArray(s).reduce((s: string, c: number) => s + String.fromCharCode(c), '');
}