// extract-source-from-source-map.js
const fs = require("fs")
const path = require("path")
const util = require("util")
const source = require("source-map")
const writeFile = util.promisify(fs.writeFile)
const mapFile = process.argv[2]
if (!mapFile) {
console.error('no input file given')
process.exit(1)
}
// 读取“mapFile”路径下的所有.map文件
let dir = fs.readdirSync(mapFile)
dir = dir.filter((name) => /\.map$/.test(name)).map(name => `${mapFile}${name}`)
for (const valueMap of dir) {
console.log("map file start: ", valueMap);
const mapFileContent = fs.readFileSync(valueMap, 'utf-8')
const outputDir = path.join(__dirname, 'output')
fs.mkdirSync(outputDir, {
recursive: true
})
new source.SourceMapConsumer(mapFileContent).then(consumer => {
Promise.all(consumer.sources.map(async (source) => {
const content = consumer.sourceContentFor(source)
const outputPath = path.join(outputDir, source)
fs.mkdirSync(path.dirname(outputPath), {
recursive: true
})
return writeFile(outputPath, content)
}))
}).catch(console.error)
}
，我来为大家讲解一下关于sourcemap的原理?跟着小编一起来看一看吧!
sourcemap的原理
通过source-map恢复源文件还原脚本
// extract-source-from-source-map.js
const fs = require("fs")
const path = require("path")
const util = require("util")
const source = require("source-map")
const writeFile = util.promisify(fs.writeFile)
const mapFile = process.argv[2]
if (!mapFile) {
console.error('no input file given')
process.exit(1)
}
// 读取“mapFile”路径下的所有.map文件
let dir = fs.readdirSync(mapFile)
dir = dir.filter((name) => /\.map$/.test(name)).map(name => `${mapFile}${name}`)
for (const valueMap of dir) {
console.log("map file start: ", valueMap);
const mapFileContent = fs.readFileSync(valueMap, 'utf-8')
const outputDir = path.join(__dirname, 'output')
fs.mkdirSync(outputDir, {
recursive: true
})
new source.SourceMapConsumer(mapFileContent).then(consumer => {
Promise.all(consumer.sources.map(async (source) => {
const content = consumer.sourceContentFor(source)
const outputPath = path.join(outputDir, source)
fs.mkdirSync(path.dirname(outputPath), {
recursive: true
})
return writeFile(outputPath, content)
}))
}).catch(console.error)
}
运行
node extract-source-from-source-map.js [source-map文件目录]
会在extract-source-from-source-map.js文件所在目录下的output目录输出源代码
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