Sourcemaps Error - Line must be Greater than or Equal to 1, Got 0

[steve-gray]

Situation:

• Using latest version of gulp, babel, gulp-istanbul, and attempting to remap coverage outputs. Istanbul is able to process code as expected, and generates its own reports - albiet with the offsets wrong due to the babel transpilation.
• Running the gulp task for remap-istanbul causes horrible errors and death, specifically:

Stack trace:

TypeError: Line must be greater than or equal to 1, got 0 at SourceMapConsumer_findMapping as _findMapping at SourceMapConsumer_originalPositionFor as originalPositionFor at getMapping (/Users/steveg/Desktop/workspace/steve-standards/node_modules/remap-istanbul/lib/remap.js:66:25) at /Users/steveg/Desktop/workspace/steve-standards/node_modules/remap-istanbul/lib/remap.js:264:20 at Array.forEach (native) at /Users/steveg/Desktop/workspace/steve-standards/node_modules/remap-istanbul/lib/remap.js:262:44 at Array.forEach (native) at /Users/steveg/Desktop/workspace/steve-standards/node_modules/remap-istanbul/lib/remap.js:182:22 at Array.forEach (native) at remap (/Users/steveg/Desktop/workspace/steve-standards/node_modules/remap-istanbul/lib/remap.js:181:12)

Cover task:

    import * as isparta from 'isparta';
    import istanbul from 'gulp-istanbul';
    import gulp from 'gulp';

    export default () =>
    gulp.src(['./dist/**/*.js'])
        .pipe(istanbul({
        includeUntested: true,
        instrumenter: isparta.Instrumenter,
        }))
        .pipe(gulp.dest('./docs/coverage/instrumented'))
        .pipe(istanbul.hookRequire());

Test task:

    import istanbul from 'gulp-istanbul';
    import mocha from 'gulp-mocha';
    import gulp from 'gulp';
    import remapIstanbul from 'remap-istanbul/lib/gulpRemapIstanbul';

    export default () =>
    gulp.src(['./tests/**/*.spec.js'])
        .pipe(mocha({
        reporter: 'mochawesome',
        reporterOptions: {
            inlineAssets: true,
            reportTitle: 'Unit Test Report',
            reportDir: './docs/unit-tests',
        },
        }))
        .pipe(istanbul.writeReports({
        dir: './docs/coverage',
        reporters: ['json'],
        }))
        .on('end', () => gulp.src('./docs/coverage/coverage-final.json')
            .pipe(remapIstanbul({
            'json': './docs/coverage/coverage.json',
            'html': './docs/coverage/html-report'
            }))
            .pipe(gulp.dest('.')));

Instrumented code:

        const x = 5;

        function imNeverRun() {
        if (x >= 7) {
            return 2;
        } else {
            return 5;
        }
        }

        export default x;

Babel intermediate:

  "use strict";

  Object.defineProperty(exports, "__esModule", {
    value: true
  });

  var _sourceMapSupport2 = require("source-map-support");

  (0, _sourceMapSupport2.install)();
  var x = 5;

  function imNeverRun() {
    if (x >= 7) {
      return 2;
    } else {
      return 5;
    }
  }

  exports.default = x;
  module.exports = exports['default'];
  //# sourceMappingURL=index.js.map

The sourcemap:

    {"version":3,"sources":["index.js"],"names":[],"mappings":";;;;;;;;;AAAA,IAAM,IAAI,CAAV;;AAEA,SAAS,UAAT,GAAsB;AACpB,MAAI,KAAK,CAAT,EAAY;AACV,WAAO,CAAP;AACD,GAFD,MAEO;AACL,WAAO,CAAP;AACD;AACF;;kBAEc,C","file":"index.js","sourcesContent":["const x = 5;\n\nfunction imNeverRun() {\n  if (x >= 7) {\n    return 2;\n  } else {\n    return 5;\n  }\n}\n\nexport default x;\n"]}

And then the coverage-final that's generated:

    {
    "/Users/steveg/Desktop/workspace/steve-standards/dist/index.js":{"path":"/Users/steveg/Desktop/workspace/steve-standards/dist/index.js","s":{"1":0,"2":0,"3":0,"4":0,"5":0,"6":0,"7":1,"8":0,"9":0,"10":0,"11":0,"12":0},"b":{"1":[0,0]},"f":{"1":0},"fnMap":{"1":{"name":"imNeverRun","loc":{"start":{"line":12,"column":0},"end":{"line":12,"column":22}},"line":15}},"statementMap":{"1":{"start":{"line":0,"column":0},"end":{"line":0,"column":0},"skip":true},"2":{"start":{"line":0,"column":0},"end":{"line":0,"column":0},"skip":true},"3":{"end":{"line":3,"column":0},"start":{"line":3,"column":0}},"4":{"end":{"line":7,"column":0},"start":{"line":7,"column":0}},"5":{"end":{"line":9,"column":0},"start":{"line":9,"column":0}},"6":{"end":{"line":10,"column":0},"start":{"line":10,"column":0}},"7":{"end":{"line":18,"column":1},"start":{"line":12,"column":0}},"8":{"end":{"line":17,"column":3},"start":{"line":13,"column":2}},"9":{"end":{"line":14,"column":4},"start":{"line":14,"column":4}},"10":{"end":{"line":16,"column":4},"start":{"line":16,"column":4}},"11":{"end":{"line":20,"column":0},"start":{"line":20,"column":0}},"12":{"end":{"line":21,"column":0},"start":{"line":21,"column":0}}},"branchMap":{"1":{"line":16,"type":"if","locations":[{"end":{"line":13,"column":2},"start":{"line":13,"column":2}},{"end":{"line":13,"column":2},"start":{"line":13,"column":2}}]}},"l":{"0":1,"3":0,"7":0,"9":0,"10":0,"12":1,"13":0,"14":0,"16":0,"20":0,"21":0}}}

[steve-gray]

Fix located/submitted:

https://github.com/SitePen/remap-istanbul/pull/59

The issue is that the various permutations of babel transforms I'm dealing with don't always have originating lines in the source file that they belong to. These nodes come through the remap operation with the 'skip' flag, but the code ploughs on and just attempts to remap them anyway, causing the underlying soucemaps helper classes to fail with the error in my post.

-Steve

[steve-gray]

Hey @kitsonk, is there any chance of getting this published as a patch soon-ish? Otherwise I'm going to need to pump out a hacked-up version for a project :(

[kitsonk]

I will try to make time today... Though no guarantees. Thanks for all your input!

[Cheetah0723]

I also have this error in svelte. But I haven't found the answer. Please contact me.

[richfergus]

I also have this error in svelte. But I haven't found the answer. Please contact me.

Same

[Ju-bot-code]

I also have this error in svelte. But I haven't found the answer. Please contact me.

me toooo