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Disable package.json conditional exports fallback lookups #62310

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4edc039
Disable package.json conditional exports fallback lookups
andrewbranch Aug 20, 2025
1b4bbbc
Update existing baselines, unify self-name lookups to a single pass
andrewbranch Aug 20, 2025
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22 changes: 2 additions & 20 deletions src/compiler/moduleNameResolver.ts
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Original file line number Diff line number Diff line change
Expand Up @@ -37,7 +37,7 @@
forEachAncestorDirectory,
formatMessage,
getAllowImportingTsExtensions,
getAllowJSCompilerOption,

Check warning on line 40 in src/compiler/moduleNameResolver.ts

View workflow job for this annotation

GitHub Actions / lint 

'getAllowJSCompilerOption' is defined but never used. Allowed unused vars must match /^(_+$|_[^_])/u
getAnyExtensionFromPath,
getBaseFileName,
GetCanonicalFileName,
Expand Down Expand Up @@ -2586,26 +2586,7 @@
}
const trailingParts = parts.slice(nameParts.length);
const subpath = !length(trailingParts) ? "." : `.${directorySeparator}${trailingParts.join(directorySeparator)}`;
// Maybe TODO: splitting extensions into two priorities should be unnecessary, except
// https://github.com/microsoft/TypeScript/issues/50762 makes the behavior different.
// As long as that bug exists, we need to do two passes here in self-name loading
// in order to be consistent with (non-self) library-name loading in
// `loadModuleFromNearestNodeModulesDirectoryWorker`, which uses two passes in order
// to prioritize `@types` packages higher up the directory tree over untyped
// implementation packages. See the selfNameModuleAugmentation.ts test for why this
// matters.
//
// However, there's an exception. If the user has `allowJs` and `declaration`, we need
// to ensure that self-name imports of their own package can resolve back to their
// input JS files via `tryLoadInputFileForPath` at a higher priority than their output
// declaration files, so we need to do a single pass with all extensions for that case.
if (getAllowJSCompilerOption(state.compilerOptions) && !pathContainsNodeModules(directory)) {
return loadModuleFromExports(scope, extensions, subpath, state, cache, redirectedReference);
}
const priorityExtensions = extensions & (Extensions.TypeScript | Extensions.Declaration);
const secondaryExtensions = extensions & ~(Extensions.TypeScript | Extensions.Declaration);
return loadModuleFromExports(scope, priorityExtensions, subpath, state, cache, redirectedReference)
|| loadModuleFromExports(scope, secondaryExtensions, subpath, state, cache, redirectedReference);
return loadModuleFromExports(scope, extensions, subpath, state, cache, redirectedReference);
}

function loadModuleFromExports(scope: PackageJsonInfo, extensions: Extensions, subpath: string, state: ModuleResolutionState, cache: ModuleResolutionCache | undefined, redirectedReference: ResolvedProjectReference | undefined): SearchResult<Resolved> {
Expand Down Expand Up @@ -2818,6 +2799,7 @@
}
else {
traceIfEnabled(state, Diagnostics.Failed_to_resolve_under_condition_0, condition);
return { value: undefined };
}
}
else {
Expand Down
34 changes: 27 additions & 7 deletions ...lines/reference/conditionalExportsResolutionFallback(moduleresolution=bundler).trace.json
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Expand Up @@ -15,15 +15,35 @@
"File '/node_modules/dep/dist/index.mts' does not exist.",
"File '/node_modules/dep/dist/index.d.mts' does not exist.",
"Failed to resolve under condition 'import'.",
"Saw non-matching condition 'require'.",
"Matched 'exports' condition 'types'.",
"Using 'exports' subpath '.' with target './dist/index.d.ts'.",
"File '/node_modules/dep/dist/index.d.ts' exists - use it as a name resolution result.",
"Directory '/node_modules/@types' does not exist, skipping all lookups in it.",
"Searching all ancestor node_modules directories for fallback extensions: JavaScript, JSON.",
"File '/node_modules/dep/package.json' exists according to earlier cached lookups.",
"Entering conditional exports.",
"Matched 'exports' condition 'import'.",
"Using 'exports' subpath '.' with target './dist/index.mjs'.",
"File name '/node_modules/dep/dist/index.mjs' has a '.mjs' extension - stripping it.",
"File '/node_modules/dep/dist/index.mjs' exists - use it as a name resolution result.",
"'package.json' does not have a 'peerDependencies' field.",
"Resolved under condition 'types'.",
"Resolved under condition 'import'.",
"Exiting conditional exports.",
"Resolving real path for '/node_modules/dep/dist/index.d.ts', result '/node_modules/dep/dist/index.d.ts'.",
"======== Module name 'dep' was successfully resolved to '/node_modules/dep/dist/index.d.ts' with Package ID 'dep/dist/[email protected]'. ========",
"Resolution of non-relative name failed; trying with modern Node resolution features disabled to see if npm library needs configuration update.",
"File '/package.json' does not exist according to earlier cached lookups.",
"Loading module 'dep' from 'node_modules' folder, target file types: TypeScript, Declaration.",
"Searching all ancestor node_modules directories for preferred extensions: TypeScript, Declaration.",
"File '/node_modules/dep/package.json' exists according to earlier cached lookups.",
"File '/node_modules/dep.ts' does not exist.",
"File '/node_modules/dep.tsx' does not exist.",
"File '/node_modules/dep.d.ts' does not exist.",
"'package.json' does not have a 'typesVersions' field.",
"'package.json' does not have a 'typings' field.",
"'package.json' does not have a 'types' field.",
"'package.json' does not have a 'main' field.",
"File '/node_modules/dep/index.ts' does not exist.",
"File '/node_modules/dep/index.tsx' does not exist.",
"File '/node_modules/dep/index.d.ts' does not exist.",
"Directory '/node_modules/@types' does not exist, skipping all lookups in it.",
"Resolving real path for '/node_modules/dep/dist/index.mjs', result '/node_modules/dep/dist/index.mjs'.",
"======== Module name 'dep' was successfully resolved to '/node_modules/dep/dist/index.mjs' with Package ID 'dep/dist/[email protected]'. ========",
"======== Resolving module '@typescript/lib-es5' from '/.src/__lib_node_modules_lookup_lib.es5.d.ts__.ts'. ========",
"Explicitly specified module resolution kind: 'Node10'.",
"Loading module '@typescript/lib-es5' from 'node_modules' folder, target file types: TypeScript, Declaration.",
Expand Down
7 changes: 1 addition & 6 deletions ...elines/reference/conditionalExportsResolutionFallback(moduleresolution=node16).errors.txt
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Expand Up @@ -22,9 +22,4 @@ error TS5110: Option 'module' must be set to 'Node16' when option 'moduleResolut
export {};

==== /index.mts (0 errors) ====
import {} from "dep";
// Should be an untyped resolution to dep/dist/index.mjs,
// but the first search is only for TS files, and when
// there's no dist/index.d.mts, it continues looking for
// matching conditions and resolves via `types`.

import {} from "dep";
28 changes: 21 additions & 7 deletions ...elines/reference/conditionalExportsResolutionFallback(moduleresolution=node16).trace.json
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Expand Up @@ -15,15 +15,29 @@
"File '/node_modules/dep/dist/index.mts' does not exist.",
"File '/node_modules/dep/dist/index.d.mts' does not exist.",
"Failed to resolve under condition 'import'.",
"Saw non-matching condition 'require'.",
"Matched 'exports' condition 'types'.",
"Using 'exports' subpath '.' with target './dist/index.d.ts'.",
"File '/node_modules/dep/dist/index.d.ts' exists - use it as a name resolution result.",
"Directory '/node_modules/@types' does not exist, skipping all lookups in it.",
"Searching all ancestor node_modules directories for fallback extensions: JavaScript.",
"File '/node_modules/dep/package.json' exists according to earlier cached lookups.",
"Entering conditional exports.",
"Matched 'exports' condition 'import'.",
"Using 'exports' subpath '.' with target './dist/index.mjs'.",
"File name '/node_modules/dep/dist/index.mjs' has a '.mjs' extension - stripping it.",
"File '/node_modules/dep/dist/index.mjs' exists - use it as a name resolution result.",
"'package.json' does not have a 'peerDependencies' field.",
"Resolved under condition 'types'.",
"Resolved under condition 'import'.",
"Exiting conditional exports.",
"Resolving real path for '/node_modules/dep/dist/index.d.ts', result '/node_modules/dep/dist/index.d.ts'.",
"======== Module name 'dep' was successfully resolved to '/node_modules/dep/dist/index.d.ts' with Package ID 'dep/dist/[email protected]'. ========",
"Resolution of non-relative name failed; trying with modern Node resolution features disabled to see if npm library needs configuration update.",
"File '/package.json' does not exist according to earlier cached lookups.",
"Loading module 'dep' from 'node_modules' folder, target file types: TypeScript, Declaration.",
"Searching all ancestor node_modules directories for preferred extensions: TypeScript, Declaration.",
"File '/node_modules/dep/package.json' exists according to earlier cached lookups.",
"'package.json' does not have a 'typesVersions' field.",
"'package.json' does not have a 'typings' field.",
"'package.json' does not have a 'types' field.",
"'package.json' does not have a 'main' field.",
"Directory '/node_modules/@types' does not exist, skipping all lookups in it.",
"Resolving real path for '/node_modules/dep/dist/index.mjs', result '/node_modules/dep/dist/index.mjs'.",
"======== Module name 'dep' was successfully resolved to '/node_modules/dep/dist/index.mjs' with Package ID 'dep/dist/[email protected]'. ========",
"File '/.ts/package.json' does not exist.",
"File '/package.json' does not exist according to earlier cached lookups.",
"======== Resolving module '@typescript/lib-es5' from '/.src/__lib_node_modules_lookup_lib.es5.d.ts__.ts'. ========",
Expand Down
7 changes: 1 addition & 6 deletions ...ines/reference/conditionalExportsResolutionFallback(moduleresolution=nodenext).errors.txt
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Expand Up @@ -22,9 +22,4 @@ error TS5110: Option 'module' must be set to 'NodeNext' when option 'moduleResol
export {};

==== /index.mts (0 errors) ====
import {} from "dep";
// Should be an untyped resolution to dep/dist/index.mjs,
// but the first search is only for TS files, and when
// there's no dist/index.d.mts, it continues looking for
// matching conditions and resolves via `types`.

import {} from "dep";
28 changes: 21 additions & 7 deletions ...ines/reference/conditionalExportsResolutionFallback(moduleresolution=nodenext).trace.json
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Original file line number Diff line number Diff line change
Expand Up @@ -15,15 +15,29 @@
"File '/node_modules/dep/dist/index.mts' does not exist.",
"File '/node_modules/dep/dist/index.d.mts' does not exist.",
"Failed to resolve under condition 'import'.",
"Saw non-matching condition 'require'.",
"Matched 'exports' condition 'types'.",
"Using 'exports' subpath '.' with target './dist/index.d.ts'.",
"File '/node_modules/dep/dist/index.d.ts' exists - use it as a name resolution result.",
"Directory '/node_modules/@types' does not exist, skipping all lookups in it.",
"Searching all ancestor node_modules directories for fallback extensions: JavaScript.",
"File '/node_modules/dep/package.json' exists according to earlier cached lookups.",
"Entering conditional exports.",
"Matched 'exports' condition 'import'.",
"Using 'exports' subpath '.' with target './dist/index.mjs'.",
"File name '/node_modules/dep/dist/index.mjs' has a '.mjs' extension - stripping it.",
"File '/node_modules/dep/dist/index.mjs' exists - use it as a name resolution result.",
"'package.json' does not have a 'peerDependencies' field.",
"Resolved under condition 'types'.",
"Resolved under condition 'import'.",
"Exiting conditional exports.",
"Resolving real path for '/node_modules/dep/dist/index.d.ts', result '/node_modules/dep/dist/index.d.ts'.",
"======== Module name 'dep' was successfully resolved to '/node_modules/dep/dist/index.d.ts' with Package ID 'dep/dist/[email protected]'. ========",
"Resolution of non-relative name failed; trying with modern Node resolution features disabled to see if npm library needs configuration update.",
"File '/package.json' does not exist according to earlier cached lookups.",
"Loading module 'dep' from 'node_modules' folder, target file types: TypeScript, Declaration.",
"Searching all ancestor node_modules directories for preferred extensions: TypeScript, Declaration.",
"File '/node_modules/dep/package.json' exists according to earlier cached lookups.",
"'package.json' does not have a 'typesVersions' field.",
"'package.json' does not have a 'typings' field.",
"'package.json' does not have a 'types' field.",
"'package.json' does not have a 'main' field.",
"Directory '/node_modules/@types' does not exist, skipping all lookups in it.",
"Resolving real path for '/node_modules/dep/dist/index.mjs', result '/node_modules/dep/dist/index.mjs'.",
"======== Module name 'dep' was successfully resolved to '/node_modules/dep/dist/index.mjs' with Package ID 'dep/dist/[email protected]'. ========",
"File '/.ts/package.json' does not exist.",
"File '/package.json' does not exist according to earlier cached lookups.",
"======== Resolving module '@typescript/lib-es5' from '/.src/__lib_node_modules_lookup_lib.es5.d.ts__.ts'. ========",
Expand Down
4 changes: 0 additions & 4 deletions ...aselines/reference/resolvesWithoutExportsDiagnostic1(moduleresolution=bundler).trace.json
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Expand Up @@ -15,8 +15,6 @@
"File '/node_modules/foo/index.mts' does not exist.",
"File '/node_modules/foo/index.d.mts' does not exist.",
"Failed to resolve under condition 'import'.",
"Saw non-matching condition 'require'.",
"Exiting conditional exports.",
"File '/node_modules/@types/foo.d.ts' does not exist.",
"Searching all ancestor node_modules directories for fallback extensions: JavaScript, JSON.",
"File '/node_modules/foo/package.json' exists according to earlier cached lookups.",
Expand Down Expand Up @@ -56,8 +54,6 @@
"File '/node_modules/bar/index.mts' does not exist.",
"File '/node_modules/bar/index.d.mts' does not exist.",
"Failed to resolve under condition 'import'.",
"Saw non-matching condition 'require'.",
"Exiting conditional exports.",
"File '/node_modules/@types/bar/package.json' exists according to earlier cached lookups.",
"Entering conditional exports.",
"Saw non-matching condition 'require'.",
Expand Down
4 changes: 0 additions & 4 deletions ...baselines/reference/resolvesWithoutExportsDiagnostic1(moduleresolution=node16).trace.json
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Original file line number Diff line number Diff line change
Expand Up @@ -15,8 +15,6 @@
"File '/node_modules/foo/index.mts' does not exist.",
"File '/node_modules/foo/index.d.mts' does not exist.",
"Failed to resolve under condition 'import'.",
"Saw non-matching condition 'require'.",
"Exiting conditional exports.",
"Searching all ancestor node_modules directories for fallback extensions: JavaScript.",
"File '/node_modules/foo/package.json' exists according to earlier cached lookups.",
"Entering conditional exports.",
Expand Down Expand Up @@ -52,8 +50,6 @@
"File '/node_modules/bar/index.mts' does not exist.",
"File '/node_modules/bar/index.d.mts' does not exist.",
"Failed to resolve under condition 'import'.",
"Saw non-matching condition 'require'.",
"Exiting conditional exports.",
"File '/node_modules/@types/bar/package.json' exists according to earlier cached lookups.",
"Entering conditional exports.",
"Saw non-matching condition 'require'.",
Expand Down
2 changes: 1 addition & 1 deletion tests/baselines/reference/selfNameModuleAugmentation.symbols
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Expand Up @@ -3,7 +3,7 @@
=== /node_modules/acorn-walk/dist/walk.d.ts ===
export {};
declare module 'acorn-walk' {
>'acorn-walk' : Symbol("/node_modules/acorn-walk/dist/walk", Decl(walk.d.ts, 0, 0), Decl(walk.d.ts, 0, 10))
>'acorn-walk' : Symbol("/node_modules/acorn-walk/dist/walk", Decl(walk.mjs, 0, 0), Decl(walk.d.ts, 0, 10))

export function simple(node: any, visitors: any, base?: any, state?: any): any;
>simple : Symbol(simple, Decl(walk.d.ts, 1, 29))
Expand Down
46 changes: 26 additions & 20 deletions tests/baselines/reference/selfNameModuleAugmentation.trace.json
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Expand Up @@ -12,18 +12,11 @@
"File name '/node_modules/acorn-walk/dist/walk.mjs' has a '.mjs' extension - stripping it.",
"File '/node_modules/acorn-walk/dist/walk.mts' does not exist.",
"File '/node_modules/acorn-walk/dist/walk.d.mts' does not exist.",
"Failed to resolve under condition 'import'.",
"Saw non-matching condition 'require'.",
"Matched 'exports' condition 'default'.",
"Using 'exports' subpath '.' with target './dist/walk.js'.",
"File name '/node_modules/acorn-walk/dist/walk.js' has a '.js' extension - stripping it.",
"File '/node_modules/acorn-walk/dist/walk.ts' does not exist.",
"File '/node_modules/acorn-walk/dist/walk.tsx' does not exist.",
"File '/node_modules/acorn-walk/dist/walk.d.ts' exists - use it as a name resolution result.",
"File '/node_modules/acorn-walk/dist/walk.mjs' exists - use it as a name resolution result.",
"'package.json' does not have a 'peerDependencies' field.",
"Resolved under condition 'default'.",
"Resolved under condition 'import'.",
"Exiting conditional exports.",
"======== Module name 'acorn-walk' was successfully resolved to '/node_modules/acorn-walk/dist/walk.d.ts' with Package ID 'acorn-walk/dist/walk.d.ts@8.2.0'. ========",
"======== Module name 'acorn-walk' was successfully resolved to '/node_modules/acorn-walk/dist/walk.mjs' with Package ID 'acorn-walk/dist/walk.mjs@8.2.0'. ========",
"======== Resolving module 'acorn-walk' from '/index.ts'. ========",
"Explicitly specified module resolution kind: 'Bundler'.",
"Resolving in CJS mode with conditions 'import', 'types'.",
Expand All @@ -38,17 +31,30 @@
"File '/node_modules/acorn-walk/dist/walk.mts' does not exist.",
"File '/node_modules/acorn-walk/dist/walk.d.mts' does not exist.",
"Failed to resolve under condition 'import'.",
"Saw non-matching condition 'require'.",
"Matched 'exports' condition 'default'.",
"Using 'exports' subpath '.' with target './dist/walk.js'.",
"File name '/node_modules/acorn-walk/dist/walk.js' has a '.js' extension - stripping it.",
"File '/node_modules/acorn-walk/dist/walk.ts' does not exist.",
"File '/node_modules/acorn-walk/dist/walk.tsx' does not exist.",
"File '/node_modules/acorn-walk/dist/walk.d.ts' exists - use it as a name resolution result.",
"Resolved under condition 'default'.",
"Directory '/node_modules/@types' does not exist, skipping all lookups in it.",
"Searching all ancestor node_modules directories for fallback extensions: JavaScript, JSON.",
"File '/node_modules/acorn-walk/package.json' exists according to earlier cached lookups.",
"Entering conditional exports.",
"Matched 'exports' condition 'import'.",
"Using 'exports' subpath '.' with target './dist/walk.mjs'.",
"File name '/node_modules/acorn-walk/dist/walk.mjs' has a '.mjs' extension - stripping it.",
"File '/node_modules/acorn-walk/dist/walk.mjs' exists - use it as a name resolution result.",
"Resolved under condition 'import'.",
"Exiting conditional exports.",
"Resolving real path for '/node_modules/acorn-walk/dist/walk.d.ts', result '/node_modules/acorn-walk/dist/walk.d.ts'.",
"======== Module name 'acorn-walk' was successfully resolved to '/node_modules/acorn-walk/dist/walk.d.ts' with Package ID 'acorn-walk/dist/[email protected]'. ========",
"Resolution of non-relative name failed; trying with modern Node resolution features disabled to see if npm library needs configuration update.",
"File '/package.json' does not exist according to earlier cached lookups.",
"Loading module 'acorn-walk' from 'node_modules' folder, target file types: TypeScript, Declaration.",
"Searching all ancestor node_modules directories for preferred extensions: TypeScript, Declaration.",
"File '/node_modules/acorn-walk/package.json' exists according to earlier cached lookups.",
"File '/node_modules/acorn-walk.ts' does not exist.",
"File '/node_modules/acorn-walk.tsx' does not exist.",
"File '/node_modules/acorn-walk.d.ts' does not exist.",
"'package.json' does not have a 'typesVersions' field.",
"'package.json' does not have a 'typings' field.",
"'package.json' has 'types' field 'dist/walk.d.ts' that references '/node_modules/acorn-walk/dist/walk.d.ts'.",
"File '/node_modules/acorn-walk/dist/walk.d.ts' exists - use it as a name resolution result.",
"Resolving real path for '/node_modules/acorn-walk/dist/walk.mjs', result '/node_modules/acorn-walk/dist/walk.mjs'.",
"======== Module name 'acorn-walk' was successfully resolved to '/node_modules/acorn-walk/dist/walk.mjs' with Package ID 'acorn-walk/dist/[email protected]'. ========",
"======== Resolving module '@typescript/lib-es5' from '/.src/__lib_node_modules_lookup_lib.es5.d.ts__.ts'. ========",
"Explicitly specified module resolution kind: 'Node10'.",
"Loading module '@typescript/lib-es5' from 'node_modules' folder, target file types: TypeScript, Declaration.",
Expand Down
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