Support for "declare global" modules

CC: @Zamiel

Author: Gerrit0

CHANGELOG.md

@@ -1,5 +1,9 @@
 # Unreleased
 
+### Features
+
+-   Added support for documenting a module's global declarations as its exports if it contains no real exports.
+
 ### Bug Fixes
 
 -   Restore support for TS 4.0 through 4.5, #1945.

src/lib/converter/converter.ts

@@ -469,7 +469,7 @@ function getSymbolForModuleLike(
 
 function getExports(
     context: Context,
-    node: ts.SourceFile | ts.ModuleBlock,
+    node: ts.SourceFile,
     symbol: ts.Symbol | undefined
 ): ts.Symbol[] {
     let result: ts.Symbol[];
@@ -496,6 +496,27 @@ function getExports(
         result = context.checker
             .getExportsOfModule(symbol)
             .filter((s) => !hasAllFlags(s.flags, ts.SymbolFlags.Prototype));
+
+        if (result.length === 0) {
+            const globalDecl = node.statements.find(
+                (s) =>
+                    ts.isModuleDeclaration(s) &&
+                    s.flags & ts.NodeFlags.GlobalAugmentation
+            );
+
+            if (globalDecl) {
+                const globalSymbol = context.getSymbolAtLocation(globalDecl);
+                if (globalSymbol) {
+                    result = context.checker
+                        .getExportsOfModule(globalSymbol)
+                        .filter((exp) =>
+                            exp.declarations?.some(
+                                (d) => d.getSourceFile() === node
+                            )
+                        );
+                }
+            }
+        }
     } else {
         // Global file with no inferred top level symbol, get all symbols declared in this file.
         const sourceFile = node.getSourceFile();

src/test/behaviorTests.ts

@@ -81,6 +81,14 @@ export const behaviorTests: Record<
             "WithoutReadonlyNumeric"
         );
     },
+
+    declareGlobal(project) {
+        equal(
+            project.children?.map((c) => c.name),
+            ["DeclareGlobal"]
+        );
+    },
+
     duplicateHeritageClauses(project) {
         const b = query(project, "B");
         equal(b.extendedTypes?.map(String), ["A"]);

src/test/converter2/behavior/declareGlobal.ts

@@ -0,0 +1,9 @@
+import { SyntaxKind } from "typescript";
+
+declare global {
+    interface DeclareGlobal {
+        method(kind: SyntaxKind): void;
+    }
+}
+
+namespace NotIncluded {}