[Flight] Consistently encode sourceURLs #33731
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| if (filename.startsWith('/')) { | ||
| // If the filename starts with `/` we assume that it is a file system file | ||
| // rather than relative to the current host. Since on the server fully qualified | ||
| // stack traces use the file path. | ||
| // TODO: What does this look like on Windows? | ||
| filename = 'file://' + filename; | ||
| } |
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The host should deal with this instead (e.g. in Node.js via url.pathToFileURL if they need to). For CommonJS it'd be the wrong thing to do since the sourcemaps of CJS files are keyed by their file path in Node.js not their file URL.
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When a Server runs a Client reading from a third-party Server in the same VM, you might not want to implement
findSourceMapURLfor that Client in environments where HTTP is not available as a protocol insourceMappingURL(e.g. Node.js).You also won't know the source map URL of a given source in Node.js. Only its payload and serializing that into
data:URLs is too memory intensive.When you don't implement
findSourceMapURL, React always appliedencodeURIto the originlsourceURL. This caused two problems:sourceURLwas already a valid URL). You can't blindly applydecodeURIon locations in stack frames since you don't know if you're dealing with an original source URL or the source URL React encoded.findSourceMapURLreturns no source mapping URL. This breaks debuggers since the original source will be overwritten with React's fake sources ifsourceURL === encodeURI(sourceURL)Now we always use the same mechanism to create unique source URLs:
"rsc://" environmentName "/" originalSourceURL "?" fakeFunctionIdxenvironmentNameis put throughencodeURIComponent.originalSourceURLis put throughencodeURI.fakeFunctionIdxis a number with no meaning. It only exists to create unique sources.Not using
encodeURIat all doesn't work for CommonJS wheregetScriptNameOrSourceURLreturns the script name which is a file path. If we encode that into a file URL,findSourceMapwill no longer work on the source URL from that fake script.