91 lines
2.1 KiB
Markdown
91 lines
2.1 KiB
Markdown
|
# merge-source-map
|
||
|
|
|
||
|
|
[](https://npmjs.org/package/merge-source-map)
|
||
|
|
[](https://travis-ci.org/keik/merge-source-map)
|
||
|
|
[](https://coveralls.io/github/keik/merge-source-map)
|
||
|
|
|
||
|
|
Merge old source map and new source map in multi-transform flow
|
||
|
|
|
||
|
|
|
||
|
|
# API
|
||
|
|
|
||
|
|
```javascript
|
||
|
|
var merge = require('merge-source-map')
|
||
|
|
```
|
||
|
|
|
||
|
|
|
||
|
|
## `merge(oldMap, newMap)`
|
||
|
|
|
||
|
|
Merge old source map and new source map and return merged.
|
||
|
|
If old or new source map value is falsy, return another one as it is.
|
||
|
|
|
||
|
|
<dl>
|
||
|
|
<dt>
|
||
|
|
<code>oldMap</code> : <code>object|undefined</code>
|
||
|
|
</dt>
|
||
|
|
<dd>
|
||
|
|
old source map object
|
||
|
|
</dd>
|
||
|
|
|
||
|
|
<dt>
|
||
|
|
<code>newmap</code> : <code>object|undefined</code>
|
||
|
|
</dt>
|
||
|
|
<dd>
|
||
|
|
new source map object
|
||
|
|
</dd>
|
||
|
|
</dl>
|
||
|
|
|
||
|
|
|
||
|
|
# Example
|
||
|
|
|
||
|
|
```javascript
|
||
|
|
var esprima = require('esprima'),
|
||
|
|
estraverse = require('estraverse'),
|
||
|
|
escodegen = require('escodegen'),
|
||
|
|
convert = require('convert-source-map'),
|
||
|
|
merge = require('merge-source-map')
|
||
|
|
|
||
|
|
const CODE = 'a = 1',
|
||
|
|
FILEPATH = 'a.js'
|
||
|
|
|
||
|
|
// create AST of original code
|
||
|
|
var ast = esprima.parse(CODE, {sourceType: 'module', loc: true})
|
||
|
|
|
||
|
|
// transform AST of original code
|
||
|
|
estraverse.replace(ast, {
|
||
|
|
enter: function(node, parent) { /* change AST */ },
|
||
|
|
leave: function(node, parent) { /* change AST */ }
|
||
|
|
})
|
||
|
|
|
||
|
|
// generate code and source map from transformed AST
|
||
|
|
var gen = escodegen.generate(ast, {
|
||
|
|
sourceMap: FILEPATH,
|
||
|
|
sourceMapWithCode: true,
|
||
|
|
sourceContent: CODE
|
||
|
|
})
|
||
|
|
|
||
|
|
// merge old source map and new source map
|
||
|
|
var oldMap = convert.fromSource(CODE) && convert.fromSource(CODE).toObject(),
|
||
|
|
newMap = JSON.parse(gen.map.toString()),
|
||
|
|
mergedMap = merge(oldMap, newMap),
|
||
|
|
mapComment = convert.fromObject(mergedMap).toComment()
|
||
|
|
|
||
|
|
// attach merge source map to transformed code
|
||
|
|
var transformed = gen.code + '\n' + mapComment
|
||
|
|
|
||
|
|
console.log(transformed);
|
||
|
|
```
|
||
|
|
|
||
|
|
|
||
|
|
# Test
|
||
|
|
|
||
|
|
```
|
||
|
|
% npm install
|
||
|
|
% npm test
|
||
|
|
```
|
||
|
|
|
||
|
|
|
||
|
|
# License
|
||
|
|
|
||
|
|
MIT (c) keik
|