proxy.test.ts: Add POST body test and redirection tests

Closes #2377

test/proxy.test.ts

+import bodyParser from "body-parser"
 import * as express from "express"
 import * as httpserver from "./httpserver"
 import * as integration from "./integration"
 
 describe("proxy", () => {
-  let codeServer: httpserver.HttpServer | undefined
   const nhooyrDevServer = new httpserver.HttpServer()
+  let codeServer: httpserver.HttpServer | undefined
   let proxyPath: string
+  let e: express.Express
 
   beforeAll(async () => {
-    const e = express.default()
-    await nhooyrDevServer.listen(e)
-    e.get("/wsup", (req, res) => {
-      res.json("asher is the best")
+    await nhooyrDevServer.listen((req, res) => {
+      e(req, res)
     })
     proxyPath = `/proxy/${nhooyrDevServer.port()}/wsup`
-    e.get(proxyPath, (req, res) => {
-      res.json("joe is the best")
-    })
   })
 
   afterAll(async () => {
     await nhooyrDevServer.close()
   })
 
+  beforeEach(() => {
+    e = express.default()
+  })
+
   afterEach(async () => {
     if (codeServer) {
       await codeServer.close()
@@ -31,6 +32,9 @@ describe("proxy", () => {
   })
 
   it("should rewrite the base path", async () => {
+    e.get("/wsup", (req, res) => {
+      res.json("asher is the best")
+    })
     ;[, , codeServer] = await integration.setup(["--auth=none"], "")
     const resp = await codeServer.fetch(proxyPath)
     expect(resp.status).toBe(200)
@@ -39,10 +43,61 @@ describe("proxy", () => {
   })
 
   it("should not rewrite the base path", async () => {
+    e.get(proxyPath, (req, res) => {
+      res.json("joe is the best")
+    })
     ;[, , codeServer] = await integration.setup(["--auth=none", "--proxy-path-passthrough=true"], "")
     const resp = await codeServer.fetch(proxyPath)
     expect(resp.status).toBe(200)
     const json = await resp.json()
     expect(json).toBe("joe is the best")
   })
+
+  it("should rewrite redirects", async () => {
+    e.post("/wsup", (req, res) => {
+      res.redirect(307, "/finale")
+    })
+    e.post("/finale", (req, res) => {
+      res.json("redirect success")
+    })
+    ;[, , codeServer] = await integration.setup(["--auth=none"], "")
+    const resp = await codeServer.fetch(proxyPath, {
+      method: "POST",
+    })
+    expect(resp.status).toBe(200)
+    expect(await resp.json()).toBe("redirect success")
+  })
+
+  it("should not rewrite redirects", async () => {
+    const finalePath = proxyPath.replace("/wsup", "/finale")
+    e.post(proxyPath, (req, res) => {
+      res.redirect(307, finalePath)
+    })
+    e.post(finalePath, (req, res) => {
+      res.json("redirect success")
+    })
+    ;[, , codeServer] = await integration.setup(["--auth=none", "--proxy-path-passthrough=true"], "")
+    const resp = await codeServer.fetch(proxyPath, {
+      method: "POST",
+    })
+    expect(resp.status).toBe(200)
+    expect(await resp.json()).toBe("redirect success")
+  })
+
+  it("should allow post bodies", async () => {
+    e.use(bodyParser.json({ strict: false }))
+    e.post("/wsup", (req, res) => {
+      res.json(req.body)
+    })
+    ;[, , codeServer] = await integration.setup(["--auth=none"], "")
+    const resp = await codeServer.fetch(proxyPath, {
+      method: "post",
+      body: JSON.stringify("coder is the best"),
+      headers: {
+        "Content-Type": "application/json",
+      },
+    })
+    expect(resp.status).toBe(200)
+    expect(await resp.json()).toBe("coder is the best")
+  })
 })