next-openapi-gen/dist/lib/openapi-generator.js

Automatically generate OpenAPI 3.0 documentation from Next.js projects, with support for TypeScript types and Zod schemas.

import path from "path";
import fs from "fs";
import { RouteProcessor } from "./route-processor.js";
import { cleanSpec } from "./utils.js";
export class OpenApiGenerator {
    config;
    template;
    routeProcessor;
    constructor() {
        const templatePath = path.resolve("./next.openapi.json");
        this.template = JSON.parse(fs.readFileSync(templatePath, "utf-8"));
        this.config = this.getConfig();
        this.routeProcessor = new RouteProcessor(this.config);
    }
    getConfig() {
        // @ts-ignore
        const { apiDir, schemaDir, docsUrl, ui, outputFile, includeOpenApiRoutes, schemaType = "typescript" } = this.template;
        return {
            apiDir,
            schemaDir,
            docsUrl,
            ui,
            outputFile,
            includeOpenApiRoutes,
            schemaType,
        };
    }
    generate() {
        const { apiDir } = this.config;
        // Check if app router structure exists
        let appRouterApiDir = "";
        if (fs.existsSync(path.join(path.dirname(apiDir), "app", "api"))) {
            appRouterApiDir = path.join(path.dirname(apiDir), "app", "api");
            console.log(`Found app router API directory at ${appRouterApiDir}`);
        }
        // Scan pages router routes
        this.routeProcessor.scanApiRoutes(apiDir);
        // If app router directory exists, scan it as well
        if (appRouterApiDir) {
            this.routeProcessor.scanApiRoutes(appRouterApiDir);
        }
        this.template.paths = this.routeProcessor.getSwaggerPaths();
        // Add server URL for examples if not already defined
        if (!this.template.servers || this.template.servers.length === 0) {
            this.template.servers = [
                {
                    url: this.template.basePath || "",
                    description: "API server",
                },
            ];
        }
        // Ensure there's a components section if not already defined
        if (!this.template.components) {
            this.template.components = {};
        }
        // Add schemas section if not already defined
        if (!this.template.components.schemas) {
            this.template.components.schemas = {};
        }
        // Get defined schemas from the processor
        const definedSchemas = this.routeProcessor
            .getSchemaProcessor()
            .getDefinedSchemas();
        if (definedSchemas && Object.keys(definedSchemas).length > 0) {
            this.template.components.schemas = {
                ...this.template.components.schemas,
                ...definedSchemas,
            };
        }
        const openapiSpec = cleanSpec(this.template);
        return openapiSpec;
    }
}