Merge pull request #652 from pmcelhaney/routes-prefix

add a --prefix option for route prefix

.changeset/mighty-penguins-hide.md

@@ -0,0 +1,5 @@
+---
+"counterfact": minor
+---
+
+added a --prefix option to specify prefix from which routes are served (e.g. /api/v1)

.eslintrc.cjs

@@ -19,6 +19,8 @@ const rules = {
     },
   ],
 
+  "max-lines": "warn",
+
   "n/shebang": "off",
 
   "no-magic-numbers": [
@@ -30,6 +32,7 @@ const rules = {
 
   "node/file-extension-in-import": "off",
   "node/no-callback-literal": "off",
+
   "node/no-missing-import": "off",
 
   "prettier/prettier": [

bin/counterfact.js

@@ -48,6 +48,7 @@ async function main(source, destination) {
     port: options.port,
     proxyEnabled: Boolean(options.proxyUrl),
     proxyUrl: options.proxyUrl,
+    routePrefix: options.prefix,
   };
 
   debug("loading counterfact (%o)", config);
@@ -106,6 +107,10 @@ program
   .option("--swagger", "include swagger-ui")
   .option("--open", "open a browser")
   .option("--proxy-url <string>", "proxy URL")
+  .option(
+    "--prefix <string>",
+    "base path from which routes will be served (e.g. /api/v1)",
+  )
   .action(main)
   // eslint-disable-next-line sonar/process-argv
   .parse(process.argv);

docs/usage.md

@@ -32,15 +32,16 @@ Usage: counterfact [options] <openapi.yaml> [destination]
 Counterfact is a tool for generating a REST API from an OpenAPI document.
 
 Arguments:
-openapi.yaml path or URL to OpenAPI document
-destination path to generated code (default: ".")
+  openapi.yaml          path or URL to OpenAPI document
+  destination           path to generated code (default: ".")
 
 Options:
---serve start the server after generating code
---port <number> server port number (default: 3100)
---swagger include swagger-ui (implies --serve)
---open open a browser to swagger-ui (implies --swagger and --serve)
--h, --help display help for command
+  --port <number>       server port number (default: 3100)
+  --swagger             include swagger-ui
+  --open                open a browser
+  --proxy-url <string>  proxy URL
+  --prefix <string>     base path from which routes will be served (e.g. /api/v1)
+  -h, --help            display help for command
 
 ```
 

src/server/koa-middleware.ts

@@ -26,13 +26,20 @@ function addCors(ctx: Koa.ExtendableContext, headers?: IncomingHttpHeaders) {
 
 export function koaMiddleware(
   dispatcher: Dispatcher,
-  { proxyEnabled = false, proxyUrl = "" } = {},
+  { proxyEnabled = false, proxyUrl = "", routePrefix = "" } = {},
   proxy = koaProxy,
 ): Koa.Middleware {
   // eslint-disable-next-line max-statements
   return async function middleware(ctx, next) {
+    if (!ctx.request.path.startsWith(routePrefix)) {
+      // eslint-disable-next-line @typescript-eslint/no-unsafe-return
+      return await next();
+    }
+
     /* @ts-expect-error the body comes from koa-bodyparser, not sure how to fix this */
-    const { body, headers, path, query } = ctx.request;
+    const { body, headers, query } = ctx.request;
+
+    const path = ctx.request.path.slice(routePrefix.length);
 
     // eslint-disable-next-line @typescript-eslint/consistent-type-assertions
     const method = ctx.request.method as HttpMethods;

src/server/registry.ts

@@ -203,6 +203,7 @@ export class Registry {
         }
       } else {
         node = node.children[matchingChild];
+
         matchedParts.push(matchingChild);
       }
     }

test/server/koa-middleware.test.ts

@@ -263,4 +263,41 @@ describe("koa middleware", () => {
 
     expect(ctx.set).toHaveBeenCalledWith("X-Custom-Header", "custom value");
   });
+
+  it("passes the request to the dispatcher and returns the response", async () => {
+    const registry = new Registry();
+
+    registry.add("/hello", {
+      // @ts-expect-error - not obvious how to make TS happy here, and it's just a unit test
+      POST({ body }: { body: { name: string } }) {
+        return {
+          body: `Hello, ${body.name}!`,
+        };
+      },
+    });
+
+    const dispatcher = new Dispatcher(registry, new ContextRegistry());
+    const middleware = koaMiddleware(dispatcher, { routePrefix: "/api/v1" });
+    // eslint-disable-next-line @typescript-eslint/consistent-type-assertions
+    const ctx = {
+      req: {
+        path: "/api/v1/hello",
+      },
+
+      request: {
+        body: { name: "Homer" },
+        method: "POST",
+        path: "/api/v1/hello",
+      },
+
+      set: jest.fn(),
+    } as unknown as ParameterizedContext;
+
+    await middleware(ctx, async () => {
+      await Promise.resolve(undefined);
+    });
+
+    expect(ctx.status).toBe(200);
+    expect(ctx.body).toBe("Hello, Homer!");
+  });
 });