From b754fc393738ae05aad136324a0dc78787745644 Mon Sep 17 00:00:00 2001
From: TypeScript Bot <ts_bot@rcavanaugh.com>
Date: Mon, 8 Apr 2024 10:58:14 -0700
Subject: [PATCH 1/6] =?UTF-8?q?=F0=9F=A4=96=20Pick=20PR=20#57778=20(fix=20?=
 =?UTF-8?q?type=20import=20check=20for=20default-i...)=20into=20release-5.?=
 =?UTF-8?q?4=20(#58116)?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Co-authored-by: Lyu, Wei-Da <36730922+jasonlyu123@users.noreply.github.com>
---
 src/services/completions.ts                   |  3 +-
 tests/cases/fourslash/jsFileImportNoTypes2.ts | 59 +++++++++++++++++++
 2 files changed, 61 insertions(+), 1 deletion(-)
 create mode 100644 tests/cases/fourslash/jsFileImportNoTypes2.ts

diff --git a/src/services/completions.ts b/src/services/completions.ts
index f41a00c716c8b..a074492cad678 100644
--- a/src/services/completions.ts
+++ b/src/services/completions.ts
@@ -2674,7 +2674,8 @@ export function getCompletionEntriesFromSymbols(
     }
 
     function symbolAppearsToBeTypeOnly(symbol: Symbol): boolean {
-        return !(symbol.flags & SymbolFlags.Value) && (!isInJSFile(symbol.declarations?.[0]) || !!(symbol.flags & SymbolFlags.Type));
+        const flags = getCombinedLocalAndExportSymbolFlags(skipAlias(symbol, typeChecker));
+        return !(flags & SymbolFlags.Value) && (!isInJSFile(symbol.declarations?.[0]) || !!(flags & SymbolFlags.Type));
     }
 }
 
diff --git a/tests/cases/fourslash/jsFileImportNoTypes2.ts b/tests/cases/fourslash/jsFileImportNoTypes2.ts
new file mode 100644
index 0000000000000..548cf0bd3332a
--- /dev/null
+++ b/tests/cases/fourslash/jsFileImportNoTypes2.ts
@@ -0,0 +1,59 @@
+/// <reference path="fourslash.ts" />
+
+// @allowJs: true
+
+// @Filename: /default.ts
+//// export default class TestDefaultClass {}
+
+// @Filename: /defaultType.ts
+//// export default interface TestDefaultInterface {}
+
+// @Filename: /reExport/toReExport.ts
+//// export class TestClassReExport {}
+//// export interface TestInterfaceReExport {}
+
+// @Filename: /reExport/index.ts
+//// export { TestClassReExport, TestInterfaceReExport } from './toReExport';
+
+// @Filename: /exportList.ts
+//// class TestClassExportList {};
+//// interface TestInterfaceExportList {};
+//// export { TestClassExportList, TestInterfaceExportList };
+
+// @Filename: /baseline.ts
+//// export class TestClassBaseline {}
+//// export interface TestInterfaceBaseline {}
+
+// @Filename: /a.js
+//// import /**/
+
+verify.completions({
+    marker: "",
+    isNewIdentifierLocation: true,
+    exact: [
+        {
+            name: "TestClassBaseline",
+            insertText: "import { TestClassBaseline } from \"./baseline\";",
+            source: "./baseline",
+        },
+        {
+            name: "TestClassExportList",
+            insertText: "import { TestClassExportList } from \"./exportList\";",
+            source: "./exportList",
+        },
+        {
+            name: "TestClassReExport",
+            insertText: "import { TestClassReExport } from \"./reExport\";",
+            source: "./reExport",
+        },
+        {
+            name: "TestDefaultClass",
+            insertText: "import TestDefaultClass from \"./default\";",
+            source: "./default",
+        },
+    ],
+    preferences: {
+        includeCompletionsForImportStatements: true,
+        includeCompletionsWithInsertText: true,
+    }
+});

From 38a7c0587df926957d3a6e808c62c6332665572d Mon Sep 17 00:00:00 2001
From: Jake Bailey <5341706+jakebailey@users.noreply.github.com>
Date: Mon, 8 Apr 2024 11:23:02 -0700
Subject: [PATCH 2/6] release-5.4: Always set node-version for setup-node
 (#58117)

---
 .github/workflows/accept-baselines-fix-lints.yaml | 2 ++
 .github/workflows/new-release-branch.yaml         | 2 ++
 .github/workflows/nightly.yaml                    | 1 +
 .github/workflows/release-branch-artifact.yaml    | 2 ++
 .github/workflows/rich-navigation.yml             | 2 ++
 .github/workflows/set-version.yaml                | 2 ++
 .github/workflows/sync-branch.yaml                | 2 ++
 .github/workflows/twoslash-repros.yaml            | 2 ++
 8 files changed, 15 insertions(+)

diff --git a/.github/workflows/accept-baselines-fix-lints.yaml b/.github/workflows/accept-baselines-fix-lints.yaml
index 7130e01a75a88..5cce3fd378cff 100644
--- a/.github/workflows/accept-baselines-fix-lints.yaml
+++ b/.github/workflows/accept-baselines-fix-lints.yaml
@@ -21,6 +21,8 @@ jobs:
         with:
           token: ${{ secrets.TS_BOT_GITHUB_TOKEN }}
       - uses: actions/setup-node@60edb5dd545a775178f52524783378180af0d1f8 # v4.0.2
+        with:
+          node-version: 'lts/*'
 
       - name: Configure Git, Run Tests, Update Baselines, Apply Fixes
         run: |
diff --git a/.github/workflows/new-release-branch.yaml b/.github/workflows/new-release-branch.yaml
index 23efbe1a8bf5b..5b9fe42816b59 100644
--- a/.github/workflows/new-release-branch.yaml
+++ b/.github/workflows/new-release-branch.yaml
@@ -24,6 +24,8 @@ jobs:
           fetch-depth: 0 # Default is 1; need to set to 0 to get the benefits of blob:none.
           token: ${{ secrets.TS_BOT_GITHUB_TOKEN }}
       - uses: actions/setup-node@60edb5dd545a775178f52524783378180af0d1f8 # v4.0.2
+        with:
+          node-version: 'lts/*'
       - run: |
           npm --version
           # corepack enable npm
diff --git a/.github/workflows/nightly.yaml b/.github/workflows/nightly.yaml
index 9aa7910403fc3..fb08905dc2faf 100644
--- a/.github/workflows/nightly.yaml
+++ b/.github/workflows/nightly.yaml
@@ -26,6 +26,7 @@ jobs:
       - uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4.1.1
       - uses: actions/setup-node@60edb5dd545a775178f52524783378180af0d1f8 # v4.0.2
         with:
+          node-version: 'lts/*'
           # Use NODE_AUTH_TOKEN environment variable to authenticate to this registry.
           registry-url: https://registry.npmjs.org/
       - run: |
diff --git a/.github/workflows/release-branch-artifact.yaml b/.github/workflows/release-branch-artifact.yaml
index 99862ff6066a2..af238ceeabb3a 100644
--- a/.github/workflows/release-branch-artifact.yaml
+++ b/.github/workflows/release-branch-artifact.yaml
@@ -21,6 +21,8 @@ jobs:
     steps:
       - uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4.1.1
       - uses: actions/setup-node@60edb5dd545a775178f52524783378180af0d1f8 # v4.0.2
+        with:
+          node-version: 'lts/*'
       - run: |
           npm --version
           # corepack enable npm
diff --git a/.github/workflows/rich-navigation.yml b/.github/workflows/rich-navigation.yml
index 798658d44a343..d0bc7146826f2 100644
--- a/.github/workflows/rich-navigation.yml
+++ b/.github/workflows/rich-navigation.yml
@@ -27,6 +27,8 @@ jobs:
       - uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4.1.1
 
       - uses: actions/setup-node@60edb5dd545a775178f52524783378180af0d1f8 # v4.0.2
+        with:
+          node-version: 'lts/*'
 
       - name: Install dependencies
         run: npm ci
diff --git a/.github/workflows/set-version.yaml b/.github/workflows/set-version.yaml
index 43cf921ad312a..6ca38dcd3cfe6 100644
--- a/.github/workflows/set-version.yaml
+++ b/.github/workflows/set-version.yaml
@@ -22,6 +22,8 @@ jobs:
           ref: ${{ github.event.client_payload.branch_name }}
           token: ${{ secrets.TS_BOT_GITHUB_TOKEN }}
       - uses: actions/setup-node@60edb5dd545a775178f52524783378180af0d1f8 # v4.0.2
+        with:
+          node-version: 'lts/*'
       - run: |
           npm --version
           # corepack enable npm
diff --git a/.github/workflows/sync-branch.yaml b/.github/workflows/sync-branch.yaml
index b754e945a78b5..5a4efac9a79fc 100644
--- a/.github/workflows/sync-branch.yaml
+++ b/.github/workflows/sync-branch.yaml
@@ -24,6 +24,8 @@ jobs:
 
     steps:
       - uses: actions/setup-node@60edb5dd545a775178f52524783378180af0d1f8 # v4.0.2
+        with:
+          node-version: 'lts/*'
       - uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4.1.1
         with:
           ref: ${{ github.event.inputs.branch_name || github.event.client_payload.branch_name }}
diff --git a/.github/workflows/twoslash-repros.yaml b/.github/workflows/twoslash-repros.yaml
index 5f389f70bbea2..33c0f83a8e146 100644
--- a/.github/workflows/twoslash-repros.yaml
+++ b/.github/workflows/twoslash-repros.yaml
@@ -41,6 +41,8 @@ jobs:
       - if: ${{ !github.event.inputs.bisect }}
         uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4.1.1
       - uses: actions/setup-node@60edb5dd545a775178f52524783378180af0d1f8 # v4.0.2
+        with:
+          node-version: 'lts/*'
       - uses: microsoft/TypeScript-Twoslash-Repro-Action@8680b5b290d48a7badbc7ba65971d526c61b86b8 # master
         with:
           github-token: ${{ secrets.TS_BOT_GITHUB_TOKEN }}

From 892936f4a18ded0216ae1c805a9890ebb8572fe3 Mon Sep 17 00:00:00 2001
From: TypeScript Bot <ts_bot@rcavanaugh.com>
Date: Tue, 9 Apr 2024 12:10:17 -0700
Subject: [PATCH 3/6] =?UTF-8?q?=F0=9F=A4=96=20Pick=20PR=20#58083=20(Don't?=
 =?UTF-8?q?=20propagate=20partial=20union/inter...)=20into=20release-5.4?=
 =?UTF-8?q?=20(#58136)?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Co-authored-by: Anders Hejlsberg <andersh@microsoft.com>
---
 src/compiler/checker.ts                       |  8 ++--
 ...ialUnionPropertyCacheInconsistentErrors.ts | 45 +++++++++++++++++++
 2 files changed, 50 insertions(+), 3 deletions(-)
 create mode 100644 tests/cases/fourslash/partialUnionPropertyCacheInconsistentErrors.ts

diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index 175caa9eef16e..c3d194211c56a 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -14788,8 +14788,9 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
     // these partial properties when identifying discriminant properties, but otherwise they are filtered out
     // and do not appear to be present in the union type.
     function getUnionOrIntersectionProperty(type: UnionOrIntersectionType, name: __String, skipObjectFunctionPropertyAugment?: boolean): Symbol | undefined {
-        let property = type.propertyCacheWithoutObjectFunctionPropertyAugment?.get(name) ||
-                !skipObjectFunctionPropertyAugment ? type.propertyCache?.get(name) : undefined;
+        let property = skipObjectFunctionPropertyAugment ?
+            type.propertyCacheWithoutObjectFunctionPropertyAugment?.get(name) :
+            type.propertyCache?.get(name);
         if (!property) {
             property = createUnionOrIntersectionProperty(type, name, skipObjectFunctionPropertyAugment);
             if (property) {
@@ -14797,7 +14798,8 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
                     type.propertyCacheWithoutObjectFunctionPropertyAugment ||= createSymbolTable() :
                     type.propertyCache ||= createSymbolTable();
                 properties.set(name, property);
-                if (skipObjectFunctionPropertyAugment && !type.propertyCache?.get(name)) {
+                // Propagate an entry from the non-augmented cache to the augmented cache unless the property is partial.
+                if (skipObjectFunctionPropertyAugment && !(getCheckFlags(property) & CheckFlags.Partial) && !type.propertyCache?.get(name)) {
                     const properties = type.propertyCache ||= createSymbolTable();
                     properties.set(name, property);
                 }
diff --git a/tests/cases/fourslash/partialUnionPropertyCacheInconsistentErrors.ts b/tests/cases/fourslash/partialUnionPropertyCacheInconsistentErrors.ts
new file mode 100644
index 0000000000000..7d793b520fa05
--- /dev/null
+++ b/tests/cases/fourslash/partialUnionPropertyCacheInconsistentErrors.ts
@@ -0,0 +1,45 @@
+/// <reference path="fourslash.ts" />
+
+// @strict: true
+// @lib: esnext
+
+//// interface ComponentOptions<Props> {
+////   setup?: (props: Props) => void;
+////   name?: string;
+//// }
+//// 
+//// interface FunctionalComponent<P> {
+////   (props: P): void;
+//// }
+//// 
+//// type ConcreteComponent<Props> =
+////   | ComponentOptions<Props>
+////   | FunctionalComponent<Props>;
+//// 
+//// type Component<Props = {}> = ConcreteComponent<Props>;
+//// 
+//// type WithInstallPlugin = { _prefix?: string };
+//// 
+//// 
+//// /**/
+//// export function withInstall<C extends Component, T extends WithInstallPlugin>(
+////   component: C | C[],
+////   target?: T,
+//// ): string {
+////   const componentWithInstall = (target ?? component) as T;
+////   const components = Array.isArray(component) ? component : [component];
+//// 
+////   const { name } = components[0];
+////   if (name) {
+////     return name;
+////   }
+//// 
+////   return "";
+//// }
+
+verify.noErrors();
+
+goTo.marker();
+edit.insert("type C = Component['name']");
+
+verify.noErrors();
\ No newline at end of file

From 71b2f84741f94e1414e41af8c65293a030d39945 Mon Sep 17 00:00:00 2001
From: TypeScript Bot <typescriptbot@microsoft.com>
Date: Tue, 9 Apr 2024 22:14:13 +0000
Subject: [PATCH 4/6] Bump version to 5.4.5 and LKG

---
 lib/tsc.js                 | 6 +++---
 lib/tsserver.js            | 9 +++++----
 lib/typescript.js          | 9 +++++----
 lib/typingsInstaller.js    | 2 +-
 package-lock.json          | 4 ++--
 package.json               | 2 +-
 src/compiler/corePublic.ts | 2 +-
 7 files changed, 18 insertions(+), 16 deletions(-)

diff --git a/lib/tsc.js b/lib/tsc.js
index eb9b776f9c9d8..65842cbb9ff2e 100644
--- a/lib/tsc.js
+++ b/lib/tsc.js
@@ -18,7 +18,7 @@ and limitations under the License.
 
 // src/compiler/corePublic.ts
 var versionMajorMinor = "5.4";
-var version = "5.4.4";
+var version = "5.4.5";
 
 // src/compiler/core.ts
 var emptyArray = [];
@@ -55510,13 +55510,13 @@ function createTypeChecker(host) {
   }
   function getUnionOrIntersectionProperty(type, name, skipObjectFunctionPropertyAugment) {
     var _a, _b, _c;
-    let property = ((_a = type.propertyCacheWithoutObjectFunctionPropertyAugment) == null ? void 0 : _a.get(name)) || !skipObjectFunctionPropertyAugment ? (_b = type.propertyCache) == null ? void 0 : _b.get(name) : void 0;
+    let property = skipObjectFunctionPropertyAugment ? (_a = type.propertyCacheWithoutObjectFunctionPropertyAugment) == null ? void 0 : _a.get(name) : (_b = type.propertyCache) == null ? void 0 : _b.get(name);
     if (!property) {
       property = createUnionOrIntersectionProperty(type, name, skipObjectFunctionPropertyAugment);
       if (property) {
         const properties = skipObjectFunctionPropertyAugment ? type.propertyCacheWithoutObjectFunctionPropertyAugment || (type.propertyCacheWithoutObjectFunctionPropertyAugment = createSymbolTable()) : type.propertyCache || (type.propertyCache = createSymbolTable());
         properties.set(name, property);
-        if (skipObjectFunctionPropertyAugment && !((_c = type.propertyCache) == null ? void 0 : _c.get(name))) {
+        if (skipObjectFunctionPropertyAugment && !(getCheckFlags(property) & 48 /* Partial */) && !((_c = type.propertyCache) == null ? void 0 : _c.get(name))) {
           const properties2 = type.propertyCache || (type.propertyCache = createSymbolTable());
           properties2.set(name, property);
         }
diff --git a/lib/tsserver.js b/lib/tsserver.js
index 6a1c0318396c8..d704e03c5e9c1 100644
--- a/lib/tsserver.js
+++ b/lib/tsserver.js
@@ -2340,7 +2340,7 @@ module.exports = __toCommonJS(server_exports);
 
 // src/compiler/corePublic.ts
 var versionMajorMinor = "5.4";
-var version = "5.4.4";
+var version = "5.4.5";
 var Comparison = /* @__PURE__ */ ((Comparison3) => {
   Comparison3[Comparison3["LessThan"] = -1] = "LessThan";
   Comparison3[Comparison3["EqualTo"] = 0] = "EqualTo";
@@ -60254,13 +60254,13 @@ function createTypeChecker(host) {
   }
   function getUnionOrIntersectionProperty(type, name, skipObjectFunctionPropertyAugment) {
     var _a, _b, _c;
-    let property = ((_a = type.propertyCacheWithoutObjectFunctionPropertyAugment) == null ? void 0 : _a.get(name)) || !skipObjectFunctionPropertyAugment ? (_b = type.propertyCache) == null ? void 0 : _b.get(name) : void 0;
+    let property = skipObjectFunctionPropertyAugment ? (_a = type.propertyCacheWithoutObjectFunctionPropertyAugment) == null ? void 0 : _a.get(name) : (_b = type.propertyCache) == null ? void 0 : _b.get(name);
     if (!property) {
       property = createUnionOrIntersectionProperty(type, name, skipObjectFunctionPropertyAugment);
       if (property) {
         const properties = skipObjectFunctionPropertyAugment ? type.propertyCacheWithoutObjectFunctionPropertyAugment || (type.propertyCacheWithoutObjectFunctionPropertyAugment = createSymbolTable()) : type.propertyCache || (type.propertyCache = createSymbolTable());
         properties.set(name, property);
-        if (skipObjectFunctionPropertyAugment && !((_c = type.propertyCache) == null ? void 0 : _c.get(name))) {
+        if (skipObjectFunctionPropertyAugment && !(getCheckFlags(property) & 48 /* Partial */) && !((_c = type.propertyCache) == null ? void 0 : _c.get(name))) {
           const properties2 = type.propertyCache || (type.propertyCache = createSymbolTable());
           properties2.set(name, property);
         }
@@ -160459,7 +160459,8 @@ function getCompletionEntriesFromSymbols(symbols, entries, replacementToken, con
   }
   function symbolAppearsToBeTypeOnly(symbol) {
     var _a;
-    return !(symbol.flags & 111551 /* Value */) && (!isInJSFile((_a = symbol.declarations) == null ? void 0 : _a[0]) || !!(symbol.flags & 788968 /* Type */));
+    const flags = getCombinedLocalAndExportSymbolFlags(skipAlias(symbol, typeChecker));
+    return !(flags & 111551 /* Value */) && (!isInJSFile((_a = symbol.declarations) == null ? void 0 : _a[0]) || !!(flags & 788968 /* Type */));
   }
 }
 function getLabelCompletionAtPosition(node) {
diff --git a/lib/typescript.js b/lib/typescript.js
index 018350e49dbc2..8668f6089c8c7 100644
--- a/lib/typescript.js
+++ b/lib/typescript.js
@@ -35,7 +35,7 @@ var ts = (() => {
     "src/compiler/corePublic.ts"() {
       "use strict";
       versionMajorMinor = "5.4";
-      version = "5.4.4";
+      version = "5.4.5";
       Comparison = /* @__PURE__ */ ((Comparison3) => {
         Comparison3[Comparison3["LessThan"] = -1] = "LessThan";
         Comparison3[Comparison3["EqualTo"] = 0] = "EqualTo";
@@ -58009,13 +58009,13 @@ ${lanes.join("\n")}
     }
     function getUnionOrIntersectionProperty(type, name, skipObjectFunctionPropertyAugment) {
       var _a, _b, _c;
-      let property = ((_a = type.propertyCacheWithoutObjectFunctionPropertyAugment) == null ? void 0 : _a.get(name)) || !skipObjectFunctionPropertyAugment ? (_b = type.propertyCache) == null ? void 0 : _b.get(name) : void 0;
+      let property = skipObjectFunctionPropertyAugment ? (_a = type.propertyCacheWithoutObjectFunctionPropertyAugment) == null ? void 0 : _a.get(name) : (_b = type.propertyCache) == null ? void 0 : _b.get(name);
       if (!property) {
         property = createUnionOrIntersectionProperty(type, name, skipObjectFunctionPropertyAugment);
         if (property) {
           const properties = skipObjectFunctionPropertyAugment ? type.propertyCacheWithoutObjectFunctionPropertyAugment || (type.propertyCacheWithoutObjectFunctionPropertyAugment = createSymbolTable()) : type.propertyCache || (type.propertyCache = createSymbolTable());
           properties.set(name, property);
-          if (skipObjectFunctionPropertyAugment && !((_c = type.propertyCache) == null ? void 0 : _c.get(name))) {
+          if (skipObjectFunctionPropertyAugment && !(getCheckFlags(property) & 48 /* Partial */) && !((_c = type.propertyCache) == null ? void 0 : _c.get(name))) {
             const properties2 = type.propertyCache || (type.propertyCache = createSymbolTable());
             properties2.set(name, property);
           }
@@ -159682,7 +159682,8 @@ ${newComment.split("\n").map((c) => ` * ${c}`).join("\n")}
     }
     function symbolAppearsToBeTypeOnly(symbol) {
       var _a;
-      return !(symbol.flags & 111551 /* Value */) && (!isInJSFile((_a = symbol.declarations) == null ? void 0 : _a[0]) || !!(symbol.flags & 788968 /* Type */));
+      const flags = getCombinedLocalAndExportSymbolFlags(skipAlias(symbol, typeChecker));
+      return !(flags & 111551 /* Value */) && (!isInJSFile((_a = symbol.declarations) == null ? void 0 : _a[0]) || !!(flags & 788968 /* Type */));
     }
   }
   function getLabelCompletionAtPosition(node) {
diff --git a/lib/typingsInstaller.js b/lib/typingsInstaller.js
index 9c8eb8b080270..e84a729bbc1b0 100644
--- a/lib/typingsInstaller.js
+++ b/lib/typingsInstaller.js
@@ -54,7 +54,7 @@ var path = __toESM(require("path"));
 
 // src/compiler/corePublic.ts
 var versionMajorMinor = "5.4";
-var version = "5.4.4";
+var version = "5.4.5";
 
 // src/compiler/core.ts
 var emptyArray = [];
diff --git a/package-lock.json b/package-lock.json
index 81ae0832de0a4..79a30fd716021 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,12 +1,12 @@
 {
     "name": "typescript",
-    "version": "5.4.4",
+    "version": "5.4.5",
     "lockfileVersion": 2,
     "requires": true,
     "packages": {
         "": {
             "name": "typescript",
-            "version": "5.4.4",
+            "version": "5.4.5",
             "license": "Apache-2.0",
             "bin": {
                 "tsc": "bin/tsc",
diff --git a/package.json b/package.json
index 96a0b9aefca81..f25964993ac18 100644
--- a/package.json
+++ b/package.json
@@ -2,7 +2,7 @@
     "name": "typescript",
     "author": "Microsoft Corp.",
     "homepage": "https://www.typescriptlang.org/",
-    "version": "5.4.4",
+    "version": "5.4.5",
     "license": "Apache-2.0",
     "description": "TypeScript is a language for application scale JavaScript development",
     "keywords": [
diff --git a/src/compiler/corePublic.ts b/src/compiler/corePublic.ts
index cea0a82974f1c..cf534f3db3af5 100644
--- a/src/compiler/corePublic.ts
+++ b/src/compiler/corePublic.ts
@@ -4,7 +4,7 @@ export const versionMajorMinor = "5.4";
 // The following is baselined as a literal template type without intervention
 /** The version of the TypeScript compiler release */
 // eslint-disable-next-line @typescript-eslint/no-inferrable-types
-export const version = "5.4.4" as string;
+export const version = "5.4.5" as string;
 
 /**
  * Type of objects whose values are all of the same type.

From 9f33bf1cd586a4028928d30b1bfe521788ec4da4 Mon Sep 17 00:00:00 2001
From: TypeScript Bot <ts_bot@rcavanaugh.com>
Date: Tue, 9 Apr 2024 18:38:50 -0700
Subject: [PATCH 5/6] =?UTF-8?q?=F0=9F=A4=96=20Pick=20PR=20#58098=20(Fix=20?=
 =?UTF-8?q?constraints=20of=20nested=20homomorph...)=20into=20release-5.4?=
 =?UTF-8?q?=20(#58118)?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
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Co-authored-by: Anders Hejlsberg <andersh@microsoft.com>
---
 src/compiler/checker.ts                       | 18 ++++---
 .../homomorphicMappedTypeNesting.symbols      | 51 +++++++++++++++++++
 .../homomorphicMappedTypeNesting.types        | 25 +++++++++
 .../compiler/homomorphicMappedTypeNesting.ts  | 16 ++++++
 4 files changed, 103 insertions(+), 7 deletions(-)
 create mode 100644 tests/baselines/reference/homomorphicMappedTypeNesting.symbols
 create mode 100644 tests/baselines/reference/homomorphicMappedTypeNesting.types
 create mode 100644 tests/cases/compiler/homomorphicMappedTypeNesting.ts

diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index c3d194211c56a..b2f5047e9d3ce 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -14552,16 +14552,20 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
         return type.resolvedApparentType || (type.resolvedApparentType = getResolvedApparentTypeOfMappedType(type));
     }
 
-    function getResolvedApparentTypeOfMappedType(type: MappedType) {
+    function getResolvedApparentTypeOfMappedType(type: MappedType): Type {
         const target = (type.target ?? type) as MappedType;
         const typeVariable = getHomomorphicTypeVariable(target);
         if (typeVariable && !target.declaration.nameType) {
-            const constraint = getConstraintTypeFromMappedType(type);
-            if (constraint.flags & TypeFlags.Index) {
-                const baseConstraint = getBaseConstraintOfType((constraint as IndexType).type);
-                if (baseConstraint && everyType(baseConstraint, t => isArrayOrTupleType(t) || isArrayOrTupleOrIntersection(t))) {
-                    return instantiateType(target, prependTypeMapping(typeVariable, baseConstraint, type.mapper));
-                }
+            // We have a homomorphic mapped type or an instantiation of a homomorphic mapped type, i.e. a type
+            // of the form { [P in keyof T]: X }. Obtain the modifiers type (the T of the keyof T), and if it is
+            // another generic mapped type, recursively obtain its apparent type. Otherwise, obtain its base
+            // constraint. Then, if every constituent of the base constraint is an array or tuple type, apply
+            // this mapped type to the base constraint. It is safe to recurse when the modifiers type is a
+            // mapped type because we protect again circular constraints in getTypeFromMappedTypeNode.
+            const modifiersType = getModifiersTypeFromMappedType(type);
+            const baseConstraint = isGenericMappedType(modifiersType) ? getApparentTypeOfMappedType(modifiersType) : getBaseConstraintOfType(modifiersType);
+            if (baseConstraint && everyType(baseConstraint, t => isArrayOrTupleType(t) || isArrayOrTupleOrIntersection(t))) {
+                return instantiateType(target, prependTypeMapping(typeVariable, baseConstraint, type.mapper));
             }
         }
         return type;
diff --git a/tests/baselines/reference/homomorphicMappedTypeNesting.symbols b/tests/baselines/reference/homomorphicMappedTypeNesting.symbols
new file mode 100644
index 0000000000000..da939c18d6efb
--- /dev/null
+++ b/tests/baselines/reference/homomorphicMappedTypeNesting.symbols
@@ -0,0 +1,51 @@
+//// [tests/cases/compiler/homomorphicMappedTypeNesting.ts] ////
+
+=== homomorphicMappedTypeNesting.ts ===
+// Repro from #58060
+
+type Box<T extends string> = { v: T };
+>Box : Symbol(Box, Decl(homomorphicMappedTypeNesting.ts, 0, 0))
+>T : Symbol(T, Decl(homomorphicMappedTypeNesting.ts, 2, 9))
+>v : Symbol(v, Decl(homomorphicMappedTypeNesting.ts, 2, 30))
+>T : Symbol(T, Decl(homomorphicMappedTypeNesting.ts, 2, 9))
+
+type Test<T extends string[]> = T
+>Test : Symbol(Test, Decl(homomorphicMappedTypeNesting.ts, 2, 38))
+>T : Symbol(T, Decl(homomorphicMappedTypeNesting.ts, 4, 10))
+>T : Symbol(T, Decl(homomorphicMappedTypeNesting.ts, 4, 10))
+
+type UnboxArray<T> = {
+>UnboxArray : Symbol(UnboxArray, Decl(homomorphicMappedTypeNesting.ts, 4, 33))
+>T : Symbol(T, Decl(homomorphicMappedTypeNesting.ts, 6, 16))
+
+    [K in keyof T]: T[K] extends Box<infer R> ? R : never;
+>K : Symbol(K, Decl(homomorphicMappedTypeNesting.ts, 7, 5))
+>T : Symbol(T, Decl(homomorphicMappedTypeNesting.ts, 6, 16))
+>T : Symbol(T, Decl(homomorphicMappedTypeNesting.ts, 6, 16))
+>K : Symbol(K, Decl(homomorphicMappedTypeNesting.ts, 7, 5))
+>Box : Symbol(Box, Decl(homomorphicMappedTypeNesting.ts, 0, 0))
+>R : Symbol(R, Decl(homomorphicMappedTypeNesting.ts, 7, 42))
+>R : Symbol(R, Decl(homomorphicMappedTypeNesting.ts, 7, 42))
+
+};
+
+type Identity<T> = { [K in keyof T]: T[K] };
+>Identity : Symbol(Identity, Decl(homomorphicMappedTypeNesting.ts, 8, 2))
+>T : Symbol(T, Decl(homomorphicMappedTypeNesting.ts, 10, 14))
+>K : Symbol(K, Decl(homomorphicMappedTypeNesting.ts, 10, 22))
+>T : Symbol(T, Decl(homomorphicMappedTypeNesting.ts, 10, 14))
+>T : Symbol(T, Decl(homomorphicMappedTypeNesting.ts, 10, 14))
+>K : Symbol(K, Decl(homomorphicMappedTypeNesting.ts, 10, 22))
+
+declare function fnBad<T extends Array<Box<string>>>(...args: T): Test<Identity<UnboxArray<T>>>;
+>fnBad : Symbol(fnBad, Decl(homomorphicMappedTypeNesting.ts, 10, 44))
+>T : Symbol(T, Decl(homomorphicMappedTypeNesting.ts, 12, 23))
+>Array : Symbol(Array, Decl(lib.es5.d.ts, --, --), Decl(lib.es5.d.ts, --, --))
+>Box : Symbol(Box, Decl(homomorphicMappedTypeNesting.ts, 0, 0))
+>args : Symbol(args, Decl(homomorphicMappedTypeNesting.ts, 12, 53))
+>T : Symbol(T, Decl(homomorphicMappedTypeNesting.ts, 12, 23))
+>Test : Symbol(Test, Decl(homomorphicMappedTypeNesting.ts, 2, 38))
+>Identity : Symbol(Identity, Decl(homomorphicMappedTypeNesting.ts, 8, 2))
+>UnboxArray : Symbol(UnboxArray, Decl(homomorphicMappedTypeNesting.ts, 4, 33))
+>T : Symbol(T, Decl(homomorphicMappedTypeNesting.ts, 12, 23))
+
diff --git a/tests/baselines/reference/homomorphicMappedTypeNesting.types b/tests/baselines/reference/homomorphicMappedTypeNesting.types
new file mode 100644
index 0000000000000..82eb61f12bc6e
--- /dev/null
+++ b/tests/baselines/reference/homomorphicMappedTypeNesting.types
@@ -0,0 +1,25 @@
+//// [tests/cases/compiler/homomorphicMappedTypeNesting.ts] ////
+
+=== homomorphicMappedTypeNesting.ts ===
+// Repro from #58060
+
+type Box<T extends string> = { v: T };
+>Box : Box<T>
+>v : T
+
+type Test<T extends string[]> = T
+>Test : T
+
+type UnboxArray<T> = {
+>UnboxArray : UnboxArray<T>
+
+    [K in keyof T]: T[K] extends Box<infer R> ? R : never;
+};
+
+type Identity<T> = { [K in keyof T]: T[K] };
+>Identity : Identity<T>
+
+declare function fnBad<T extends Array<Box<string>>>(...args: T): Test<Identity<UnboxArray<T>>>;
+>fnBad : <T extends Box<string>[]>(...args: T) => Test<Identity<UnboxArray<T>>>
+>args : T
+
diff --git a/tests/cases/compiler/homomorphicMappedTypeNesting.ts b/tests/cases/compiler/homomorphicMappedTypeNesting.ts
new file mode 100644
index 0000000000000..630c4d40cf51d
--- /dev/null
+++ b/tests/cases/compiler/homomorphicMappedTypeNesting.ts
@@ -0,0 +1,16 @@
+// @strict: true
+// @noEmit: true
+
+// Repro from #58060
+
+type Box<T extends string> = { v: T };
+
+type Test<T extends string[]> = T
+
+type UnboxArray<T> = {
+    [K in keyof T]: T[K] extends Box<infer R> ? R : never;
+};
+
+type Identity<T> = { [K in keyof T]: T[K] };
+
+declare function fnBad<T extends Array<Box<string>>>(...args: T): Test<Identity<UnboxArray<T>>>;

From 27bcd4cb5a98bce46c9cdd749752703ead021a4b Mon Sep 17 00:00:00 2001
From: TypeScript Bot <typescriptbot@microsoft.com>
Date: Wed, 10 Apr 2024 01:40:12 +0000
Subject: [PATCH 6/6] Update LKG

---
 lib/tsc.js        | 10 ++++------
 lib/tsserver.js   | 10 ++++------
 lib/typescript.js | 10 ++++------
 3 files changed, 12 insertions(+), 18 deletions(-)

diff --git a/lib/tsc.js b/lib/tsc.js
index 65842cbb9ff2e..f4e4fed2bc00f 100644
--- a/lib/tsc.js
+++ b/lib/tsc.js
@@ -55344,12 +55344,10 @@ function createTypeChecker(host) {
     const target = type.target ?? type;
     const typeVariable = getHomomorphicTypeVariable(target);
     if (typeVariable && !target.declaration.nameType) {
-      const constraint = getConstraintTypeFromMappedType(type);
-      if (constraint.flags & 4194304 /* Index */) {
-        const baseConstraint = getBaseConstraintOfType(constraint.type);
-        if (baseConstraint && everyType(baseConstraint, (t) => isArrayOrTupleType(t) || isArrayOrTupleOrIntersection(t))) {
-          return instantiateType(target, prependTypeMapping(typeVariable, baseConstraint, type.mapper));
-        }
+      const modifiersType = getModifiersTypeFromMappedType(type);
+      const baseConstraint = isGenericMappedType(modifiersType) ? getApparentTypeOfMappedType(modifiersType) : getBaseConstraintOfType(modifiersType);
+      if (baseConstraint && everyType(baseConstraint, (t) => isArrayOrTupleType(t) || isArrayOrTupleOrIntersection(t))) {
+        return instantiateType(target, prependTypeMapping(typeVariable, baseConstraint, type.mapper));
       }
     }
     return type;
diff --git a/lib/tsserver.js b/lib/tsserver.js
index d704e03c5e9c1..3f1ce62663e3c 100644
--- a/lib/tsserver.js
+++ b/lib/tsserver.js
@@ -60088,12 +60088,10 @@ function createTypeChecker(host) {
     const target = type.target ?? type;
     const typeVariable = getHomomorphicTypeVariable(target);
     if (typeVariable && !target.declaration.nameType) {
-      const constraint = getConstraintTypeFromMappedType(type);
-      if (constraint.flags & 4194304 /* Index */) {
-        const baseConstraint = getBaseConstraintOfType(constraint.type);
-        if (baseConstraint && everyType(baseConstraint, (t) => isArrayOrTupleType(t) || isArrayOrTupleOrIntersection(t))) {
-          return instantiateType(target, prependTypeMapping(typeVariable, baseConstraint, type.mapper));
-        }
+      const modifiersType = getModifiersTypeFromMappedType(type);
+      const baseConstraint = isGenericMappedType(modifiersType) ? getApparentTypeOfMappedType(modifiersType) : getBaseConstraintOfType(modifiersType);
+      if (baseConstraint && everyType(baseConstraint, (t) => isArrayOrTupleType(t) || isArrayOrTupleOrIntersection(t))) {
+        return instantiateType(target, prependTypeMapping(typeVariable, baseConstraint, type.mapper));
       }
     }
     return type;
diff --git a/lib/typescript.js b/lib/typescript.js
index 8668f6089c8c7..22053b17844ef 100644
--- a/lib/typescript.js
+++ b/lib/typescript.js
@@ -57843,12 +57843,10 @@ ${lanes.join("\n")}
       const target = type.target ?? type;
       const typeVariable = getHomomorphicTypeVariable(target);
       if (typeVariable && !target.declaration.nameType) {
-        const constraint = getConstraintTypeFromMappedType(type);
-        if (constraint.flags & 4194304 /* Index */) {
-          const baseConstraint = getBaseConstraintOfType(constraint.type);
-          if (baseConstraint && everyType(baseConstraint, (t) => isArrayOrTupleType(t) || isArrayOrTupleOrIntersection(t))) {
-            return instantiateType(target, prependTypeMapping(typeVariable, baseConstraint, type.mapper));
-          }
+        const modifiersType = getModifiersTypeFromMappedType(type);
+        const baseConstraint = isGenericMappedType(modifiersType) ? getApparentTypeOfMappedType(modifiersType) : getBaseConstraintOfType(modifiersType);
+        if (baseConstraint && everyType(baseConstraint, (t) => isArrayOrTupleType(t) || isArrayOrTupleOrIntersection(t))) {
+          return instantiateType(target, prependTypeMapping(typeVariable, baseConstraint, type.mapper));
         }
       }
       return type;

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