Default to true

src/compiler/commandLineParser.ts

@@ -861,7 +861,7 @@ const commandOptionsWithoutBuild: CommandLineOption[] = [
         affectsProgramStructure: true,
         category: Diagnostics.Language_and_Environment,
         description: Diagnostics.Enable_lib_replacement,
-        defaultValueDescription: false,
+        defaultValueDescription: true,
     },
 
     // Strict Type Checks

src/compiler/program.ts

@@ -4065,7 +4065,7 @@ export function createProgram(rootNamesOrOptions: readonly string[] | CreateProg
         const existing = resolvedLibProcessing?.get(libFileName);
         if (existing) return existing;
 
-        if (!options.libReplacement) {
+        if (options.libReplacement === false) {
             const result: LibResolution = {
                 resolution: {
                     resolvedModule: undefined,

tests/baselines/reference/allowJsCrossMonorepoPackage.trace.json

@@ -75,5 +75,89 @@
     "======== Module name 'pkg' was successfully resolved to '/node_modules/pkg/index.d.ts'. ========",
     "File '/node_modules/pkg/package.json' does not exist according to earlier cached lookups.",
     "File '/node_modules/package.json' does not exist.",
-    "File '/package.json' does not exist."
+    "File '/package.json' does not exist.",
+    "======== Resolving module '@typescript/lib-es5' from '/packages/main/__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.",
+    "Searching all ancestor node_modules directories for preferred extensions: TypeScript, Declaration.",
+    "Directory '/packages/main/node_modules/@types' does not exist, skipping all lookups in it.",
+    "Scoped package detected, looking in 'typescript__lib-es5'",
+    "Directory '/packages/node_modules' does not exist, skipping all lookups in it.",
+    "Scoped package detected, looking in 'typescript__lib-es5'",
+    "Directory '/node_modules/@types' does not exist, skipping all lookups in it.",
+    "Scoped package detected, looking in 'typescript__lib-es5'",
+    "Loading module '@typescript/lib-es5' from 'node_modules' folder, target file types: JavaScript.",
+    "Searching all ancestor node_modules directories for fallback extensions: JavaScript.",
+    "Directory '/packages/node_modules' does not exist, skipping all lookups in it.",
+    "======== Module name '@typescript/lib-es5' was not resolved. ========",
+    "======== Resolving module '@typescript/lib-decorators' from '/packages/main/__lib_node_modules_lookup_lib.decorators.d.ts__.ts'. ========",
+    "Explicitly specified module resolution kind: 'Node10'.",
+    "Loading module '@typescript/lib-decorators' from 'node_modules' folder, target file types: TypeScript, Declaration.",
+    "Searching all ancestor node_modules directories for preferred extensions: TypeScript, Declaration.",
+    "Directory '/packages/main/node_modules/@types' does not exist, skipping all lookups in it.",
+    "Scoped package detected, looking in 'typescript__lib-decorators'",
+    "Directory '/packages/node_modules' does not exist, skipping all lookups in it.",
+    "Scoped package detected, looking in 'typescript__lib-decorators'",
+    "Directory '/node_modules/@types' does not exist, skipping all lookups in it.",
+    "Scoped package detected, looking in 'typescript__lib-decorators'",
+    "Loading module '@typescript/lib-decorators' from 'node_modules' folder, target file types: JavaScript.",
+    "Searching all ancestor node_modules directories for fallback extensions: JavaScript.",
+    "Directory '/packages/node_modules' does not exist, skipping all lookups in it.",
+    "======== Module name '@typescript/lib-decorators' was not resolved. ========",
+    "======== Resolving module '@typescript/lib-decorators/legacy' from '/packages/main/__lib_node_modules_lookup_lib.decorators.legacy.d.ts__.ts'. ========",
+    "Explicitly specified module resolution kind: 'Node10'.",
+    "Loading module '@typescript/lib-decorators/legacy' from 'node_modules' folder, target file types: TypeScript, Declaration.",
+    "Searching all ancestor node_modules directories for preferred extensions: TypeScript, Declaration.",
+    "Directory '/packages/main/node_modules/@types' does not exist, skipping all lookups in it.",
+    "Scoped package detected, looking in 'typescript__lib-decorators/legacy'",
+    "Directory '/packages/node_modules' does not exist, skipping all lookups in it.",
+    "Scoped package detected, looking in 'typescript__lib-decorators/legacy'",
+    "Directory '/node_modules/@types' does not exist, skipping all lookups in it.",
+    "Scoped package detected, looking in 'typescript__lib-decorators/legacy'",
+    "Loading module '@typescript/lib-decorators/legacy' from 'node_modules' folder, target file types: JavaScript.",
+    "Searching all ancestor node_modules directories for fallback extensions: JavaScript.",
+    "Directory '/packages/node_modules' does not exist, skipping all lookups in it.",
+    "======== Module name '@typescript/lib-decorators/legacy' was not resolved. ========",
+    "======== Resolving module '@typescript/lib-dom' from '/packages/main/__lib_node_modules_lookup_lib.dom.d.ts__.ts'. ========",
+    "Explicitly specified module resolution kind: 'Node10'.",
+    "Loading module '@typescript/lib-dom' from 'node_modules' folder, target file types: TypeScript, Declaration.",
+    "Searching all ancestor node_modules directories for preferred extensions: TypeScript, Declaration.",
+    "Directory '/packages/main/node_modules/@types' does not exist, skipping all lookups in it.",
+    "Scoped package detected, looking in 'typescript__lib-dom'",
+    "Directory '/packages/node_modules' does not exist, skipping all lookups in it.",
+    "Scoped package detected, looking in 'typescript__lib-dom'",
+    "Directory '/node_modules/@types' does not exist, skipping all lookups in it.",
+    "Scoped package detected, looking in 'typescript__lib-dom'",
+    "Loading module '@typescript/lib-dom' from 'node_modules' folder, target file types: JavaScript.",
+    "Searching all ancestor node_modules directories for fallback extensions: JavaScript.",
+    "Directory '/packages/node_modules' does not exist, skipping all lookups in it.",
+    "======== Module name '@typescript/lib-dom' was not resolved. ========",
+    "======== Resolving module '@typescript/lib-webworker/importscripts' from '/packages/main/__lib_node_modules_lookup_lib.webworker.importscripts.d.ts__.ts'. ========",
+    "Explicitly specified module resolution kind: 'Node10'.",
+    "Loading module '@typescript/lib-webworker/importscripts' from 'node_modules' folder, target file types: TypeScript, Declaration.",
+    "Searching all ancestor node_modules directories for preferred extensions: TypeScript, Declaration.",
+    "Directory '/packages/main/node_modules/@types' does not exist, skipping all lookups in it.",
+    "Scoped package detected, looking in 'typescript__lib-webworker/importscripts'",
+    "Directory '/packages/node_modules' does not exist, skipping all lookups in it.",
+    "Scoped package detected, looking in 'typescript__lib-webworker/importscripts'",
+    "Directory '/node_modules/@types' does not exist, skipping all lookups in it.",
+    "Scoped package detected, looking in 'typescript__lib-webworker/importscripts'",
+    "Loading module '@typescript/lib-webworker/importscripts' from 'node_modules' folder, target file types: JavaScript.",
+    "Searching all ancestor node_modules directories for fallback extensions: JavaScript.",
+    "Directory '/packages/node_modules' does not exist, skipping all lookups in it.",
+    "======== Module name '@typescript/lib-webworker/importscripts' was not resolved. ========",
+    "======== Resolving module '@typescript/lib-scripthost' from '/packages/main/__lib_node_modules_lookup_lib.scripthost.d.ts__.ts'. ========",
+    "Explicitly specified module resolution kind: 'Node10'.",
+    "Loading module '@typescript/lib-scripthost' from 'node_modules' folder, target file types: TypeScript, Declaration.",
+    "Searching all ancestor node_modules directories for preferred extensions: TypeScript, Declaration.",
+    "Directory '/packages/main/node_modules/@types' does not exist, skipping all lookups in it.",
+    "Scoped package detected, looking in 'typescript__lib-scripthost'",
+    "Directory '/packages/node_modules' does not exist, skipping all lookups in it.",
+    "Scoped package detected, looking in 'typescript__lib-scripthost'",
+    "Directory '/node_modules/@types' does not exist, skipping all lookups in it.",
+    "Scoped package detected, looking in 'typescript__lib-scripthost'",
+    "Loading module '@typescript/lib-scripthost' from 'node_modules' folder, target file types: JavaScript.",
+    "Searching all ancestor node_modules directories for fallback extensions: JavaScript.",
+    "Directory '/packages/node_modules' does not exist, skipping all lookups in it.",
+    "======== Module name '@typescript/lib-scripthost' was not resolved. ========"
 ]

tests/baselines/reference/bundlerConditionsExcludesNode(module=esnext).trace.json

@@ -20,5 +20,77 @@
     "Resolved under condition 'default'.",
     "Exiting conditional exports.",
     "Resolving real path for '/node_modules/conditions/index.web.d.ts', result '/node_modules/conditions/index.web.d.ts'.",
-    "======== Module name 'conditions' was successfully resolved to '/node_modules/conditions/index.web.d.ts' with Package ID 'conditions/[email protected]'. ========"
+    "======== Module name 'conditions' was successfully resolved to '/node_modules/conditions/index.web.d.ts' with Package ID 'conditions/[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.",
+    "Searching all ancestor node_modules directories for preferred extensions: TypeScript, Declaration.",
+    "Directory '/.src/node_modules' does not exist, skipping all lookups in it.",
+    "Scoped package detected, looking in 'typescript__lib-es5'",
+    "Directory '/node_modules/@types' does not exist, skipping all lookups in it.",
+    "Scoped package detected, looking in 'typescript__lib-es5'",
+    "Loading module '@typescript/lib-es5' from 'node_modules' folder, target file types: JavaScript.",
+    "Searching all ancestor node_modules directories for fallback extensions: JavaScript.",
+    "Directory '/.src/node_modules' does not exist, skipping all lookups in it.",
+    "======== Module name '@typescript/lib-es5' was not resolved. ========",
+    "======== Resolving module '@typescript/lib-decorators' from '/.src/__lib_node_modules_lookup_lib.decorators.d.ts__.ts'. ========",
+    "Explicitly specified module resolution kind: 'Node10'.",
+    "Loading module '@typescript/lib-decorators' from 'node_modules' folder, target file types: TypeScript, Declaration.",
+    "Searching all ancestor node_modules directories for preferred extensions: TypeScript, Declaration.",
+    "Directory '/.src/node_modules' does not exist, skipping all lookups in it.",
+    "Scoped package detected, looking in 'typescript__lib-decorators'",
+    "Directory '/node_modules/@types' does not exist, skipping all lookups in it.",
+    "Scoped package detected, looking in 'typescript__lib-decorators'",
+    "Loading module '@typescript/lib-decorators' from 'node_modules' folder, target file types: JavaScript.",
+    "Searching all ancestor node_modules directories for fallback extensions: JavaScript.",
+    "Directory '/.src/node_modules' does not exist, skipping all lookups in it.",
+    "======== Module name '@typescript/lib-decorators' was not resolved. ========",
+    "======== Resolving module '@typescript/lib-decorators/legacy' from '/.src/__lib_node_modules_lookup_lib.decorators.legacy.d.ts__.ts'. ========",
+    "Explicitly specified module resolution kind: 'Node10'.",
+    "Loading module '@typescript/lib-decorators/legacy' from 'node_modules' folder, target file types: TypeScript, Declaration.",
+    "Searching all ancestor node_modules directories for preferred extensions: TypeScript, Declaration.",
+    "Directory '/.src/node_modules' does not exist, skipping all lookups in it.",
+    "Scoped package detected, looking in 'typescript__lib-decorators/legacy'",
+    "Directory '/node_modules/@types' does not exist, skipping all lookups in it.",
+    "Scoped package detected, looking in 'typescript__lib-decorators/legacy'",
+    "Loading module '@typescript/lib-decorators/legacy' from 'node_modules' folder, target file types: JavaScript.",
+    "Searching all ancestor node_modules directories for fallback extensions: JavaScript.",
+    "Directory '/.src/node_modules' does not exist, skipping all lookups in it.",
+    "======== Module name '@typescript/lib-decorators/legacy' was not resolved. ========",
+    "======== Resolving module '@typescript/lib-dom' from '/.src/__lib_node_modules_lookup_lib.dom.d.ts__.ts'. ========",
+    "Explicitly specified module resolution kind: 'Node10'.",
+    "Loading module '@typescript/lib-dom' from 'node_modules' folder, target file types: TypeScript, Declaration.",
+    "Searching all ancestor node_modules directories for preferred extensions: TypeScript, Declaration.",
+    "Directory '/.src/node_modules' does not exist, skipping all lookups in it.",
+    "Scoped package detected, looking in 'typescript__lib-dom'",
+    "Directory '/node_modules/@types' does not exist, skipping all lookups in it.",
+    "Scoped package detected, looking in 'typescript__lib-dom'",
+    "Loading module '@typescript/lib-dom' from 'node_modules' folder, target file types: JavaScript.",
+    "Searching all ancestor node_modules directories for fallback extensions: JavaScript.",
+    "Directory '/.src/node_modules' does not exist, skipping all lookups in it.",
+    "======== Module name '@typescript/lib-dom' was not resolved. ========",
+    "======== Resolving module '@typescript/lib-webworker/importscripts' from '/.src/__lib_node_modules_lookup_lib.webworker.importscripts.d.ts__.ts'. ========",
+    "Explicitly specified module resolution kind: 'Node10'.",
+    "Loading module '@typescript/lib-webworker/importscripts' from 'node_modules' folder, target file types: TypeScript, Declaration.",
+    "Searching all ancestor node_modules directories for preferred extensions: TypeScript, Declaration.",
+    "Directory '/.src/node_modules' does not exist, skipping all lookups in it.",
+    "Scoped package detected, looking in 'typescript__lib-webworker/importscripts'",
+    "Directory '/node_modules/@types' does not exist, skipping all lookups in it.",
+    "Scoped package detected, looking in 'typescript__lib-webworker/importscripts'",
+    "Loading module '@typescript/lib-webworker/importscripts' from 'node_modules' folder, target file types: JavaScript.",
+    "Searching all ancestor node_modules directories for fallback extensions: JavaScript.",
+    "Directory '/.src/node_modules' does not exist, skipping all lookups in it.",
+    "======== Module name '@typescript/lib-webworker/importscripts' was not resolved. ========",
+    "======== Resolving module '@typescript/lib-scripthost' from '/.src/__lib_node_modules_lookup_lib.scripthost.d.ts__.ts'. ========",
+    "Explicitly specified module resolution kind: 'Node10'.",
+    "Loading module '@typescript/lib-scripthost' from 'node_modules' folder, target file types: TypeScript, Declaration.",
+    "Searching all ancestor node_modules directories for preferred extensions: TypeScript, Declaration.",
+    "Directory '/.src/node_modules' does not exist, skipping all lookups in it.",
+    "Scoped package detected, looking in 'typescript__lib-scripthost'",
+    "Directory '/node_modules/@types' does not exist, skipping all lookups in it.",
+    "Scoped package detected, looking in 'typescript__lib-scripthost'",
+    "Loading module '@typescript/lib-scripthost' from 'node_modules' folder, target file types: JavaScript.",
+    "Searching all ancestor node_modules directories for fallback extensions: JavaScript.",
+    "Directory '/.src/node_modules' does not exist, skipping all lookups in it.",
+    "======== Module name '@typescript/lib-scripthost' was not resolved. ========"
 ]