Handle exported interfaces

Author: michaldudak

src/parsers/exportParser.ts

@@ -59,7 +59,12 @@ export function parseExport(
 				return;
 			}
 
-			const type = checker.getTypeOfSymbol(targetSymbol);
+			let type: ts.Type;
+			if (targetSymbol.declarations?.length) {
+				type = checker.getTypeAtLocation(targetSymbol.declarations[0]);
+			} else {
+				type = checker.getTypeOfSymbol(targetSymbol);
+			}
 			return createExportNode(exportSymbol.name, targetSymbol, type, parentNamespaces);
 		} else if (ts.isExportAssignment(exportDeclaration)) {
 			// export default x
@@ -96,6 +101,19 @@ export function parseExport(
 
 			const type = checker.getTypeOfSymbol(exportedSymbol);
 			return createExportNode(exportSymbol.name, exportedSymbol, type, parentNamespaces);
+		} else if (ts.isInterfaceDeclaration(exportDeclaration)) {
+			// export interface X {}
+			if (!exportDeclaration.name) {
+				return;
+			}
+
+			const exportedSymbol = checker.getSymbolAtLocation(exportDeclaration.name);
+			if (!exportedSymbol) {
+				return;
+			}
+
+			const type = checker.getTypeAtLocation(exportDeclaration);
+			return createExportNode(exportSymbol.name, exportedSymbol, type, parentNamespaces);
 		} else if (ts.isEnumDeclaration(exportDeclaration)) {
 			// export enum x {}
 			if (!exportDeclaration.name) {

test/generics/input.ts

@@ -4,7 +4,7 @@ export function genericFunction<T extends React.HTMLAttributes<HTMLElement>>(
 	return params.value;
 }
 
-export interface GenericFunctionParameters<T extends React.HTMLAttributes<HTMLElement>> {
+interface GenericFunctionParameters<T extends React.HTMLAttributes<HTMLElement>> {
 	value: T;
 	nestedGenericType: GenericInterface<GenericInterface<string>>;
 }

test/interfaces/input.ts

@@ -0,0 +1,19 @@
+export interface Interface1 {
+	s: string;
+}
+
+interface Interface2 {
+	n: number;
+}
+
+export type { Interface2 };
+export type { Interface2 as Interface2Alias };
+
+export interface Interface1 {
+	b: boolean;
+}
+
+export default interface DefaultInterface {
+	n1: number;
+	n2?: number;
+}

test/interfaces/output.json

@@ -0,0 +1,110 @@
+{
+	"name": "test/interfaces/input",
+	"exports": [
+		{
+			"name": "Interface1",
+			"type": {
+				"kind": "object",
+				"name": "Interface1",
+				"parentNamespaces": [],
+				"properties": [
+					{
+						"name": "s",
+						"type": {
+							"kind": "intrinsic",
+							"parentNamespaces": [],
+							"name": "string"
+						},
+						"optional": false
+					},
+					{
+						"name": "b",
+						"type": {
+							"kind": "intrinsic",
+							"parentNamespaces": [],
+							"name": "boolean"
+						},
+						"optional": false
+					}
+				]
+			}
+		},
+		{
+			"name": "Interface2",
+			"type": {
+				"kind": "object",
+				"name": "Interface2",
+				"parentNamespaces": [],
+				"properties": [
+					{
+						"name": "n",
+						"type": {
+							"kind": "intrinsic",
+							"parentNamespaces": [],
+							"name": "number"
+						},
+						"optional": false
+					}
+				]
+			}
+		},
+		{
+			"name": "Interface2Alias",
+			"type": {
+				"kind": "object",
+				"name": "Interface2",
+				"parentNamespaces": [],
+				"properties": [
+					{
+						"name": "n",
+						"type": {
+							"kind": "intrinsic",
+							"parentNamespaces": [],
+							"name": "number"
+						},
+						"optional": false
+					}
+				]
+			}
+		},
+		{
+			"name": "default",
+			"type": {
+				"kind": "object",
+				"name": "default",
+				"parentNamespaces": [],
+				"properties": [
+					{
+						"name": "n1",
+						"type": {
+							"kind": "intrinsic",
+							"parentNamespaces": [],
+							"name": "number"
+						},
+						"optional": false
+					},
+					{
+						"name": "n2",
+						"type": {
+							"kind": "union",
+							"types": [
+								{
+									"kind": "intrinsic",
+									"parentNamespaces": [],
+									"name": "number"
+								},
+								{
+									"kind": "intrinsic",
+									"parentNamespaces": [],
+									"name": "undefined"
+								}
+							],
+							"parentNamespaces": []
+						},
+						"optional": true
+					}
+				]
+			}
+		}
+	]
+}

test/literal-unions/input.tsx

@@ -11,7 +11,7 @@ export function test2(
 
 export function test3(prop: keyof Params) {}
 
-export interface Params {
+interface Params {
 	inlineStringUnion: 'foo' | 'bar' | 'baz';
 	inlineNumberUnion: 1 | 2 | 3;
 	referencedStringUnion: StringUnion;

test/namespaces/output.json

@@ -171,6 +171,41 @@
 				]
 			}
 		},
+		{
+			"name": "Params",
+			"type": {
+				"kind": "object",
+				"name": "Params",
+				"parentNamespaces": [
+					"Root",
+					"Sub"
+				],
+				"properties": [
+					{
+						"name": "s",
+						"type": {
+							"kind": "enum",
+							"name": "Grade",
+							"parentNamespaces": [
+								"Root",
+								"Sub"
+							],
+							"members": [
+								{
+									"name": "good",
+									"value": 0
+								},
+								{
+									"name": "bad",
+									"value": 1
+								}
+							]
+						},
+						"optional": false
+					}
+				]
+			}
+		},
 		{
 			"name": "Grade",
 			"type": {