microsoft/vscode-react-native
Publicmirrored from https://github.com/microsoft/vscode-react-nativeAvailable
src/utils/sourceMap.ts
109lines · modecode
| 1 | import url = require("url"); |
| 2 | import path = require("path"); |
| 3 | |
| 4 | interface ISourceMap { |
| 5 | file: string; |
| 6 | sources: string[]; |
| 7 | version: number; |
| 8 | names: string[]; |
| 9 | mappings: string; |
| 10 | sourceRoot?: string; |
| 11 | sourcesContent?: string[]; |
| 12 | } |
| 13 | |
| 14 | export class SourceMapUtil { |
| 15 | /** |
| 16 | * Given a script body and URL, this method parses the body and finds the corresponding source map URL. |
| 17 | * If the source map URL is not found in the body in the expected form, null is returned. |
| 18 | */ |
| 19 | public getSourceMapURL(scriptUrl: url.Url, scriptBody: string): url.Url { |
| 20 | let result: url.Url = null; |
| 21 | |
| 22 | // scriptUrl = "http://localhost:8081/index.ios.bundle?platform=ios&dev=true" |
| 23 | let sourceMappingRelativeUrl = this.getSourceMapRelativeUrl(scriptBody); // sourceMappingRelativeUrl = "/index.ios.map?platform=ios&dev=true" |
| 24 | if (sourceMappingRelativeUrl) { |
| 25 | let sourceMappingUrl = url.parse(sourceMappingRelativeUrl); |
| 26 | sourceMappingUrl.protocol = scriptUrl.protocol; |
| 27 | sourceMappingUrl.host = scriptUrl.host; |
| 28 | // parse() repopulates all the properties of the URL |
| 29 | result = url.parse(url.format(sourceMappingUrl)); |
| 30 | } |
| 31 | |
| 32 | return result; |
| 33 | } |
| 34 | |
| 35 | /** |
| 36 | * Updates the contents of a source map file to be VS Code friendly: |
| 37 | * - makes source paths unix style and relative to the sources root path |
| 38 | * - updates the url of the script file |
| 39 | * - deletes the script content from the source map |
| 40 | * |
| 41 | * @parameter sourceMapBody - body of the source map as generated by the RN Packager. |
| 42 | * @parameter scriptPath - path of the script file asssociated with this source map. |
| 43 | * @parameter sourcesRootPath - root path of sources |
| 44 | * |
| 45 | */ |
| 46 | public updateSourceMapFile(sourceMapBody: string, scriptPath: string, sourcesRootPath: string): string { |
| 47 | try { |
| 48 | let sourceMap = <ISourceMap>JSON.parse(sourceMapBody); |
| 49 | sourceMap.sources = sourceMap.sources.map(sourcePath => { |
| 50 | return this.updateSourceMapPath(sourcePath, sourcesRootPath); |
| 51 | }); |
| 52 | |
| 53 | delete sourceMap.sourcesContent; |
| 54 | sourceMap.sourceRoot = ""; |
| 55 | sourceMap.file = scriptPath; |
| 56 | return JSON.stringify(sourceMap); |
| 57 | } catch (exception) { |
| 58 | return sourceMapBody; |
| 59 | } |
| 60 | } |
| 61 | |
| 62 | /** |
| 63 | * Given an absolute source path, this method does two things: |
| 64 | * 1. It changes the path from absolute to be relative to the sourcesRootPath parameter. |
| 65 | * 2. It changes the path separators to Unix style. |
| 66 | */ |
| 67 | private updateSourceMapPath(sourcePath: string, sourcesRootPath: string) { |
| 68 | let relativeSourcePath = path.relative(sourcesRootPath, sourcePath); |
| 69 | return this.makeUnixStylePath(relativeSourcePath); |
| 70 | } |
| 71 | |
| 72 | /** |
| 73 | * Visual Studio Code source mapping requires Unix style path separators. |
| 74 | * This method replaces all back-slash characters in a given string with forward-slash ones. |
| 75 | */ |
| 76 | private makeUnixStylePath(p: string): string { |
| 77 | return p.replace(/\\/g, "/"); |
| 78 | } |
| 79 | |
| 80 | /** |
| 81 | * Returns the regex used for source map url matching. |
| 82 | */ |
| 83 | private getSourceMapUrlRegex(): RegExp { |
| 84 | return /\/\/(#|@) sourceMappingURL=(.+?)\s*$/m; |
| 85 | } |
| 86 | |
| 87 | /** |
| 88 | * Parses the body of a script searching for a source map URL. |
| 89 | * It supports the following source map url styles: |
| 90 | * //# sourceMappingURL=path/to/source/map |
| 91 | * //@ sourceMappingURL=path/to/source/map |
| 92 | * |
| 93 | * Returns the first match if found, null otherwise. |
| 94 | */ |
| 95 | private getSourceMapRelativeUrl(body: string) { |
| 96 | let match = body.match(this.getSourceMapUrlRegex()); |
| 97 | // If match is null, the body doesn't contain the source map |
| 98 | return match ? match[2] : null; |
| 99 | } |
| 100 | |
| 101 | /** |
| 102 | * Updates source map URLs in the script body. |
| 103 | */ |
| 104 | public updateScriptPaths(scriptBody: string, sourceMappingUrl: url.Url) { |
| 105 | // Update the body with the new location of the source map on storage. |
| 106 | return scriptBody.replace(this.getSourceMapUrlRegex(), |
| 107 | "//# sourceMappingURL=" + path.basename(sourceMappingUrl.pathname)); |
| 108 | } |
| 109 | } |