For type emit, walk non-parent containers when those containers have aliases leading to the target (microsoft#24507)

Author: weswigham

src/compiler/checker.ts

@@ -2533,6 +2533,46 @@ namespace ts {
             return getMergedSymbol(symbol.parent && getLateBoundSymbol(symbol.parent));
         }
 
+        /**
+         * Attempts to find the symbol corresponding to the container a symbol is in - usually this
+         * is just its' `.parent`, but for locals, this value is `undefined`
+         */
+        function getContainerOfSymbol(symbol: Symbol): Symbol | undefined {
+            const container = getParentOfSymbol(symbol);
+            if (container) {
+                return container;
+            }
+            const candidate = forEach(symbol.declarations, d => !isAmbientModule(d) && d.parent && hasNonGlobalAugmentationExternalModuleSymbol(d.parent) ? getSymbolOfNode(d.parent) : undefined);
+            if (!candidate) {
+                return undefined;
+            }
+            const alias = getAliasForSymbolInContainer(candidate, symbol);
+            return alias ? candidate : undefined;
+        }
+
+        function getAliasForSymbolInContainer(container: Symbol, symbol: Symbol) {
+            if (container === getParentOfSymbol(symbol)) {
+                // fast path, `symbol` is either already the alias or isn't aliased
+                return symbol;
+            }
+            const exports = getExportsOfSymbol(container);
+            const quick = exports.get(symbol.escapedName);
+            if (quick && symbolRefersToTarget(quick)) {
+                return quick;
+            }
+            return forEachEntry(exports, exported => {
+                if (symbolRefersToTarget(exported)) {
+                    return exported;
+                }
+            });
+
+            function symbolRefersToTarget(s: Symbol) {
+                if (s === symbol || resolveSymbol(s) === symbol || resolveSymbol(s) === resolveSymbol(symbol)) {
+                    return s;
+                }
+            }
+        }
+
         function getExportSymbolOfValueSymbolIfExported(symbol: Symbol): Symbol;
         function getExportSymbolOfValueSymbolIfExported(symbol: Symbol | undefined): Symbol | undefined;
         function getExportSymbolOfValueSymbolIfExported(symbol: Symbol | undefined): Symbol | undefined {
@@ -2838,7 +2878,7 @@ namespace ts {
                     // But it can't, hence the accessible is going to be undefined, but that doesn't mean m.c is inaccessible
                     // It is accessible if the parent m is accessible because then m.c can be accessed through qualification
                     meaningToLook = getQualifiedLeftMeaning(meaning);
-                    symbol = getParentOfSymbol(symbol);
+                    symbol = getContainerOfSymbol(symbol);
                 }
 
                 // This could be a symbol that is not exported in the external module
@@ -3729,12 +3769,12 @@ namespace ts {
                         needsQualification(accessibleSymbolChain[0], context.enclosingDeclaration, accessibleSymbolChain.length === 1 ? meaning : getQualifiedLeftMeaning(meaning))) {
 
                         // Go up and add our parent.
-                        const parent = getParentOfSymbol(accessibleSymbolChain ? accessibleSymbolChain[0] : symbol);
+                        const parent = getContainerOfSymbol(accessibleSymbolChain ? accessibleSymbolChain[0] : symbol);
                         if (parent) {
                             const parentChain = getSymbolChain(parent, getQualifiedLeftMeaning(meaning), /*endOfChain*/ false);
                             if (parentChain) {
                                 parentSymbol = parent;
-                                accessibleSymbolChain = parentChain.concat(accessibleSymbolChain || [symbol]);
+                                accessibleSymbolChain = parentChain.concat(accessibleSymbolChain || [getAliasForSymbolInContainer(parent, symbol) || symbol]);
                             }
                         }
                     }

tests/baselines/reference/allowSyntheticDefaultImportsCanPaintCrossModuleDeclaration.js

@@ -0,0 +1,37 @@
+//// [tests/cases/compiler/allowSyntheticDefaultImportsCanPaintCrossModuleDeclaration.ts] ////
+
+//// [color.ts]
+interface Color {
+    c: string;
+}
+export default Color;
+//// [file1.ts]
+import Color from "./color";
+export declare function styled(): Color;
+//// [file2.ts]
+import { styled }  from "./file1";
+export const A = styled();
+
+//// [color.js]
+"use strict";
+exports.__esModule = true;
+//// [file1.js]
+"use strict";
+exports.__esModule = true;
+//// [file2.js]
+"use strict";
+exports.__esModule = true;
+var file1_1 = require("./file1");
+exports.A = file1_1.styled();
+
+
+//// [color.d.ts]
+interface Color {
+    c: string;
+}
+export default Color;
+//// [file1.d.ts]
+import Color from "./color";
+export declare function styled(): Color;
+//// [file2.d.ts]
+export declare const A: import("./color").default;

tests/baselines/reference/allowSyntheticDefaultImportsCanPaintCrossModuleDeclaration.symbols

@@ -0,0 +1,26 @@
+=== tests/cases/compiler/color.ts ===
+interface Color {
+>Color : Symbol(Color, Decl(color.ts, 0, 0))
+
+    c: string;
+>c : Symbol(Color.c, Decl(color.ts, 0, 17))
+}
+export default Color;
+>Color : Symbol(Color, Decl(color.ts, 0, 0))
+
+=== tests/cases/compiler/file1.ts ===
+import Color from "./color";
+>Color : Symbol(Color, Decl(file1.ts, 0, 6))
+
+export declare function styled(): Color;
+>styled : Symbol(styled, Decl(file1.ts, 0, 28))
+>Color : Symbol(Color, Decl(file1.ts, 0, 6))
+
+=== tests/cases/compiler/file2.ts ===
+import { styled }  from "./file1";
+>styled : Symbol(styled, Decl(file2.ts, 0, 8))
+
+export const A = styled();
+>A : Symbol(A, Decl(file2.ts, 1, 12))
+>styled : Symbol(styled, Decl(file2.ts, 0, 8))
+

tests/baselines/reference/allowSyntheticDefaultImportsCanPaintCrossModuleDeclaration.types

@@ -0,0 +1,27 @@
+=== tests/cases/compiler/color.ts ===
+interface Color {
+>Color : Color
+
+    c: string;
+>c : string
+}
+export default Color;
+>Color : Color
+
+=== tests/cases/compiler/file1.ts ===
+import Color from "./color";
+>Color : any
+
+export declare function styled(): Color;
+>styled : () => Color
+>Color : Color
+
+=== tests/cases/compiler/file2.ts ===
+import { styled }  from "./file1";
+>styled : () => import("tests/cases/compiler/color").default
+
+export const A = styled();
+>A : import("tests/cases/compiler/color").default
+>styled() : import("tests/cases/compiler/color").default
+>styled : () => import("tests/cases/compiler/color").default
+

tests/baselines/reference/importTypeGenericTypes.types

@@ -89,9 +89,9 @@ export const x: import("./foo")<{x: number}> = { x: 0, y: 0, data: {x: 12} };
 >12 : 12
 
 export let y: import("./foo2").Bar.I<{x: number}> = { a: "", b: 0, data: {x: 12} };
->y : Bar.I<{ x: number; }>
+>y : import("tests/cases/conformance/types/import/foo2").Bar.I<{ x: number; }>
 >Bar : any
->I : Bar.I<T>
+>I : import("tests/cases/conformance/types/import/foo2").Bar.I<T>
 >x : number
 >{ a: "", b: 0, data: {x: 12} } : { a: string; b: number; data: { x: number; }; }
 >a : string

tests/baselines/reference/importTypeLocal.types

@@ -66,9 +66,9 @@ export const x: import("./foo") = { x: 0, y: 0 };
 >0 : 0
 
 export let y: import("./foo2").Bar.I = { a: "", b: 0 };
->y : Bar.I
+>y : import("tests/cases/conformance/types/import/foo2").Bar.I
 >Bar : any
->I : Bar.I
+>I : import("tests/cases/conformance/types/import/foo2").Bar.I
 >{ a: "", b: 0 } : { a: string; b: number; }
 >a : string
 >"" : ""

tests/cases/compiler/allowSyntheticDefaultImportsCanPaintCrossModuleDeclaration.ts

@@ -0,0 +1,12 @@
+// @declaration: true
+// @filename: color.ts
+interface Color {
+    c: string;
+}
+export default Color;
+// @filename: file1.ts
+import Color from "./color";
+export declare function styled(): Color;
+// @filename: file2.ts
+import { styled }  from "./file1";
+export const A = styled();