Added correcting types for abstract classes if they aren't exported

Fixes #198

src/generate-output.ts

@@ -144,7 +144,7 @@ function needAddDeclareKeyword(statement: ts.Statement, nodeText: string): boole
 	// for some reason TypeScript allows to do not write `declare` keyword for ClassDeclaration, FunctionDeclaration and VariableDeclaration
 	// if it already has `export` keyword - so we need to add it
 	// to avoid TS1046: Top-level declarations in .d.ts files must start with either a 'declare' or 'export' modifier.
-	if (ts.isClassDeclaration(statement) && /^class\b/.test(nodeText)) {
+	if (ts.isClassDeclaration(statement) && (/^class\b/.test(nodeText) || /^abstract\b/.test(nodeText))) {
 		return true;
 	}
 

tests/e2e/test-cases/non-exported-abstract-class/abstract-class.d.ts

@@ -0,0 +1,2 @@
+export abstract class AbstractClass {
+}

tests/e2e/test-cases/non-exported-abstract-class/config.ts

@@ -0,0 +1,5 @@
+import { TestCaseConfig } from '../test-case-config';
+
+const config: TestCaseConfig = {};
+
+export = config;

tests/e2e/test-cases/non-exported-abstract-class/input.ts

@@ -0,0 +1,5 @@
+import { AbstractClass } from './abstract-class';
+
+export class NormalClass extends AbstractClass {
+
+}

tests/e2e/test-cases/non-exported-abstract-class/output.d.ts

@@ -0,0 +1,6 @@
+declare abstract class AbstractClass {
+}
+export declare class NormalClass extends AbstractClass {
+}
+
+export {};