Parse a source map and output the data in a way that makes sense to humans
Parse a source map and output the data in a way that makes sense to humans
This started life as a gist for the purpose of this blog post.
It reads a source map, and outputs an object with a similar structure, replacing the VLQ mappings property with a human-readable format:
``
"mappings": {
"0": [
^
└── the line number of the output file
"231 => source.js 5:64 foo"
^ ^ ^ ^
│ │ │ └── the symbol name from the source file
│ │ │
│ │ └── the line:column position in the source file
│ │
│ └── the name of the source file
│
└── the column number of the output file
]
}
`
`
npm i -g @bengourley/source-map-decoder
`
cat my-source-map.js.map | decode-source-map
This will output some not very pretty JSON so I recommend combining it with the jq tool (available on a mac with brew install jq) to pretty-print and colourise the output:
`
cat my-source-map.js.map | decode-source-map | jq .
The above command will pretty print the entire source map structure, potentially including all sources. So to just view the mappings property, use jq's selector interface:
`
cat my-source-map.js.map | decode-source-map | jq .mappings
ISC