Made class that represents type union

src/utils/typescript/typescript-union-type.ts

@@ -0,0 +1,81 @@
+import { TypeScriptFormattingOptions } from "./typescript-formatting-options";
+import { TypeScriptTypeDefinition } from "./typescript-type-definition";
+import { TypeScriptTypeLiteral } from "./typescript-type-literal";
+
+/**
+ * Represents a TypeScript union type definition.
+ */
+export class TypeScriptUnionType implements TypeScriptTypeDefinition {
+    /**
+     * An array of types that compose this union type.
+     */
+    private readonly _composingTypes: readonly TypeScriptTypeDefinition[];
+
+    /**
+     * Constructs a new {@link TypeScriptUnionType} instance.
+     *
+     * @param composingTypes - The iterable of types composing the union.
+     */
+    private constructor(composingTypes: readonly TypeScriptTypeDefinition[]) {
+        this._composingTypes = composingTypes;
+    }
+
+    /**
+     * Creates a new {@link TypeScriptUnionType} instance.
+     *
+     * @param composingTypes - The iterable of types composing the union.
+     *
+     * @returns A new {@link TypeScriptUnionType} instance.
+     */
+    static create(composingTypes: Iterable<TypeScriptTypeDefinition>): TypeScriptUnionType {
+        const composingTypesArray = [...composingTypes];
+        if (!composingTypesArray.length) {
+            composingTypesArray.push(TypeScriptTypeLiteral.NEVER);
+        }
+
+        return new TypeScriptUnionType(composingTypesArray);
+    }
+
+    /**
+     * @inheritdoc
+     */
+    get isComposite(): true {
+        return true;
+    }
+
+    /**
+     * @inheritdoc
+     */
+    get isUnion(): true {
+        return true;
+    }
+
+    /**
+     * @inheritdoc
+     */
+    get isIntersection(): false {
+        return false;
+    }
+
+    /**
+     * @inheritdoc
+     */
+    get isAlias(): false {
+        return false;
+    }
+
+    /**
+     * @inheritdoc
+     */
+    composingTypes(): Iterable<TypeScriptTypeDefinition> {
+        return this._composingTypes;
+    }
+
+    /**
+     * @inheritdoc
+     */
+    format(options?: TypeScriptFormattingOptions): string {
+        const formattedTypes = this._composingTypes.map(x => `(${x.format(options).trim()})`).join(" | ");
+        return formattedTypes;
+    }
+}