Add auto-import for the package.json imports field
#55015
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src/compiler/moduleSpecifiers.ts
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| if (typeof cachedPackageJson !== "object" && cachedPackageJson !== undefined) { | ||
| return undefined; | ||
| } | ||
| const packageJsonContent = cachedPackageJson?.contents.packageJsonContent || readJson(packageJsonPath, host as { readFile(fileName: string): string | undefined }); |
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Use JSON.parse for package.json files. readJson uses the TypeScript parser to construct an AST and then converts that to an object 😵 I’ve been meaning to audit existing uses of readJson and then rename it; I know some can be replaced.
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Yeah, I saw that 😅. I was aiming to consistent with the implementation of auto-import for the Sorry, I was thinking of some other code, I've updated it to exports field. I was thinking maybe that should be left for a seperate PR to avoid more ad-hoc handling of package.json reading?JSON.parse.
Use JSON.parse for package.json files. readJson uses the TypeScript parser to construct an AST and then converts that to an object 😵 I’ve been meaning to audit existing uses of readJson and then rename it; I know some can be replaced.
I've actually checked btw and all the usages of readJson are for reading package.jsons and the readJsonOrUndefined function that's used by readJson is only used for build info so all of them can really be replaced with JSON.parse
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I'm not sure that replacing everything with JSON.parse is generally correct, because it'll throw if the file has malformed JSON. The services project has a helper, tryParseJson, which catches this, and that's used by its createPackageJsonInfo (which then makes its package.json cache).
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Yes, JSON.parse should be in a try/catch, particularly when reading a local package.json as opposed to one in node_modules. It’s virtually impossible for a node_modules package.json to be malformed so I don’t care as much there. My point was only that we shouldn’t be creating TypeScript AST nodes and issuing parse diagnostics just to get an object representation of a JSON file.
diff --git a/src/compiler/moduleSpecifiers.ts b/src/compiler/moduleSpecifiers.ts
index 4dcf24ea4b..d6022afe4b 100644
--- a/src/compiler/moduleSpecifiers.ts
+++ b/src/compiler/moduleSpecifiers.ts
@@ -90,7 +90,6 @@ import {
pathIsBareSpecifier,
pathIsRelative,
PropertyAccessExpression,
- readJson,
removeExtension,
removeFileExtension,
removeSuffix,
@@ -894,11 +893,11 @@ function tryGetModuleNameFromPackageJsonImports(moduleFileName: string, sourceDi
}
const packageJsonPath = combinePaths(ancestorDirectoryWithPackageJson, "package.json");
const cachedPackageJson = host.getPackageJsonInfoCache?.()?.getPackageJsonInfo(packageJsonPath);
- if (typeof cachedPackageJson !== "object" && cachedPackageJson !== undefined) {
+ if (typeof cachedPackageJson !== "object" && cachedPackageJson !== undefined || !host.fileExists(packageJsonPath)) {
return undefined;
}
- const packageJsonContent = cachedPackageJson?.contents.packageJsonContent || readJson(packageJsonPath, host as { readFile(fileName: string): string | undefined });
- const imports = (packageJsonContent as any).imports;
+ const packageJsonContent = cachedPackageJson?.contents.packageJsonContent || JSON.parse(host.readFile(packageJsonPath)!);
+ const imports = packageJsonContent?.imports;
if (!imports) {
return undefined;
}
src/compiler/moduleSpecifiers.ts
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| if (typeof cachedPackageJson !== "object" && cachedPackageJson !== undefined || !host.fileExists(packageJsonPath)) { | ||
| return undefined; | ||
| } | ||
| const packageJsonContent = cachedPackageJson?.contents.packageJsonContent || JSON.parse(host.readFile(packageJsonPath)!); |
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I don't think this is a new problem as this file already has code that looks exactly like this, but I'm somewhat certain that we should be using readJson for this; if the JSON is malformed, we'll throw here and then I don't know what will happen. readJson is what's used to get stuff into the cache, and generally speaking other raw JSON.parse calls all appear to at least try/catch.
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I see that there's another thread about this at #55015 (comment); if we want to leave this JSON.parse in here given we already do that, that's fine, but overall if we're avoiding readJson because it calls the wrong JSON parser, but the alternatiive is to call JSON.parse unguarded... that feels spooky to me.
src/compiler/moduleSpecifiers.ts
Outdated
| if (typeof cachedPackageJson !== "object" && cachedPackageJson !== undefined) { | ||
| return undefined; | ||
| } | ||
| const packageJsonContent = cachedPackageJson?.contents.packageJsonContent || readJson(packageJsonPath, host as { readFile(fileName: string): string | undefined }); |
There was a problem hiding this comment.
I'm not sure that replacing everything with JSON.parse is generally correct, because it'll throw if the file has malformed JSON. The services project has a helper, tryParseJson, which catches this, and that's used by its createPackageJsonInfo (which then makes its package.json cache).
src/compiler/moduleSpecifiers.ts
Outdated
| if (typeof cachedPackageJson !== "object" && cachedPackageJson !== undefined || !host.fileExists(packageJsonPath)) { | ||
| return undefined; | ||
| } | ||
| const packageJsonContent = cachedPackageJson?.contents.packageJsonContent || JSON.parse(host.readFile(packageJsonPath)!); |
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I see that there's another thread about this at #55015 (comment); if we want to leave this JSON.parse in here given we already do that, that's fine, but overall if we're avoiding readJson because it calls the wrong JSON parser, but the alternatiive is to call JSON.parse unguarded... that feels spooky to me.
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None of the new tests test conditional imports - those probably need to be checked. Complex examples of nested conditions like
{
"imports": {
"#thing": {
"types": { "import": "./types-esm/thing.d.mts", "require": "./types/thing.d.ts" },
"default": { "import": "./esm/thing.mjs", "require": "./dist/thing.js" }
}
}
}are actually more common in the wild than you'd think for exports, and likely have just as much utility for imports.
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Just wanted to say, I'm excited about this 😍 |
|
@emmatown Almost there! |
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I would love to get this into 5.3. @emmatown, are you interested in continuing? If not, someone on the team can probably address the remaining feedback and get it ready to merge. |
See reasons at https://github.com/epicweb-dev/epic-stack/blob/main/docs/decisions/031-imports.md and vuejs/core#9919 Pending vuejs/core#9919 to be fixed Pending microsoft/TypeScript#55015 to be released
This shows a failure mode around a package which (oddly!) publishes an `index.ts` file in its root but also specifies both the `types` and `exports.types` keys in `package.json` as pointing to an emitted `.d.ts` file in a `dist` directory. If the `index.ts` is removed or renamed, `tsc` correctly uses `types` to resolve the location. This appears to have been introduced by microsoft/TypeScript#55015.
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Inspired by and in anticipation of this feature being released, I wrote https://www.webpro.nl/articles/using-subpath-imports-and-path-aliases (please let me know if there's mistakes). Thanks @emmatown and @Andarist for the hard work! |
| // @Filename: /a.ts | ||
| //// something/**/ | ||
|
|
||
| verify.importFixModuleSpecifiers("", ["#something.js"]); |
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@andrewbranch should this autocomplete #something.js? I'm investigating some stuff and I concluded the conclusion that perhaps this should actually be just #something. @module: nodenext doesn't prescribe the specifier ending - and since this package.json doesn't have a type it's an implied CJS file so the ending is optional.
note for myself: fixing this would likely depend on using getModuleSpecifierEndingPreference appropriately
Hmm, I still observe some inconsistencies elsewhere but now I concluded that this one is correct - imports/exports always require extensions (regardless of the module format).
Fixes #49492
This treats
package.json#importsas roughly equivalent tocompilerOptions#pathsin terms of deciding which specifier to use, it also preferspackage.json#importsovercompilerOptions#pathsWhile doing this, I found some broken behaviour around extension replacement which was already observable with the
package.json#exportsfield auto-import but is more visible withpackage.json#importsso this fixes that as well.autoImportPackageJsonExportsSpecifierEndsInTsshows an example of what's fixed forpackage.json#exports. That fix and test is in a seperate commit if that's easier to review