Report alignment issue when inputSourceMap from TypeScript

Here is a jest transformer I’m using:

const tsc = require("typescript")
const tsConfig = require("./tsconfig.json") || {}
const babel = require('babel-core')
const jestPreset = require('babel-preset-jest')
const babelPluginIstanbul = require('babel-plugin-istanbul').default

const createTransformer = (options) => {
	options = Object.assign({}, options, {
		plugins: (options && options.plugins) || [],
		presets: ((options && options.presets) || []).concat([jestPreset]),
		retainLines: true
	});
	delete options.cacheDirectory;
	delete options.filename;
	return {
		canInstrument: true,
		process(src, filename, config, transformOptions) {
			let inputSourceMap
			if (filename.endsWith(".ts") || filename.endsWith(".tsx")) {
				let compilerOptions = Object.assign({},
					tsConfig.compilerOptions, {
						sourceMap: true
					}
				)
				let transpileOut = tsc.transpileModule(src, {
					fileName: filename,
					compilerOptions
				});
				src = transpileOut.outputText
				inputSourceMap = JSON.parse(transpileOut.sourceMapText)
			}
			const theseOptions = Object.assign({
				filename,
				//inlineSourceMap,
			}, options);
			if (transformOptions && transformOptions.instrument) {
				theseOptions.auxiliaryCommentBefore = ' istanbul ignore next ';
				// Copied from jest-runtime transform.js
				theseOptions.plugins = theseOptions.plugins.concat([
					[
						babelPluginIstanbul, {
							inputSourceMap,
							cwd: config.rootDir,
							exclude: []
						}
					]
				]);
			}
			return babel.transform(src, theseOptions).code
		}
	};
};

module.exports = createTransformer();
module.exports.createTransformer = createTransformer;

The highlights in the coverage report is misaligned.

May be related to babel/babel#5408

Apparently babel also takes inputSourceMap as an option, but only takes inputSourceMap into account after plugins have run. I’m assuming that’s why this plugin has that option as well. But no matter what I do I get the same misalignment.

I’ve also tried having TypeScript pass the sourcemap inline, but that still does the same thing.

[MichaReiser]

My setup differs slightly. I used TypeScript -> Webpack transpiling with babel.

@lukescott Can you please upload the source maps of the transpilation pipelines (just for your demo file, istanbul). Then the source maps can be analyzed. If the mapping error already occurs in these source maps, then it is not an error caused by istanbul.

Edit: To me it seems as the input source map is not considered at all when using together with babel

[bcoe]

@lukescott just doing some issue cleanup – sounds like you did ultimately land in a good place with this bug, i.e., got everything working.