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Failed to parse source map from [path] warning

See original GitHub issue

Operating System: macOS Catalina 10.15.6
Node Version: 12.18.2
NPM Version: 6.14.5
Yarn version: 1.22.4
webpack Version: 4.43.0
source-map-loader version: 1.0.1

Actual Behavior

Failed to parse source map from [path] file: Error: ENOENT: no such file or directory, open [path] warnings are logged in the terminal (as well in the browser console log).

Remarks

It failed to load all standardized-audio-context package source map files
Seems that source-map-loader treats the path //# sourceMappingURL=/build/es2019/constants.js.map as an absolute path, what cause the failure Error: ENOENT: no such file or directory
For my test, removing the prefixed slash / from the path /build/es2019/constants.js.map fixes the issue, so:

// not work 😢
//# sourceMappingURL=/build/es2019/constants.js.map

// work 😍
//# sourceMappingURL=build/es2019/constants.js.map

Expected Behavior

No Failed to parse source map from... warnings should logged in the terminal and in the browser console log.

Code

{
  test: /\.js$/,
  enforce: 'pre',
  use: ['source-map-loader'],
},

Example of how the sourceMappingURL directive that fails looks like:

//# sourceMappingURL=/build/es2019/constants.js.map

How Do We Reproduce?

Prerequisite

Web app project that make use of source-map-loader

Steps

Install standardized-audio-context package
Import any module from standardized-audio-context into a *.js/*.ts file
Start/build the project

Issue Analytics

State:
Created 3 years ago
Comments:8 (4 by maintainers)

Top GitHub Comments

1reaction

alexander-akaitcommented, Aug 20, 2020

@shimizacken yes, let’s open an issue and wait an answer, if they will not fix it, I will think about it deeply, and provide fallback for this cases

1reaction

alexander-akaitcommented, Aug 20, 2020

@shimizacken I investigate this issue and I’m afraid to say that we cannot fix it, sourceMappingURL is strange:

//# sourceMappingURL=/build/es2019/factories/native-constant-source-node-factory.js.map

In file node_modules/standardized-audio-context/build/es2019/factories/native-constant-source-node-factory.js

it is relative to package root, but we don’t know it is package or not, this would require additional logic that would decrease performance dramatically.

Right sourceMappingURL:

//# sourceMappingURL=./native-constant-source-node-factory.js.map

//# sourceMappingURL=native-constant-source-node-factory.js.map

Ideally it should be always relative to file, not to directory/package root or other contexts

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