Add error codes to our custom errors (#959)

pyscriptjs/tests/unit/fetch.test.ts

@@ -0,0 +1,87 @@
+import { describe, it, expect, jest } from '@jest/globals'
+import { FetchError, ErrorCode } from "../../src/exceptions"
+import { robustFetch } from "../../src/fetch"
+import { Response } from 'node-fetch';
+
+describe("robustFetch", () => {
+
+  it("should return a response object", async () => {
+    global.fetch = jest.fn(() => (Promise.resolve(new Response(status="200", "Hello World"))));
+
+    const response = await robustFetch("https://pyscript.net");
+    expect(response).toBeInstanceOf(Response);
+    expect(response.status).toBe(200);
+  })
+
+  it('receiving a 404 when fetching should throw FetchError with the right errorCode', async () => {
+    global.fetch = jest.fn(() => (Promise.resolve(new Response("Not Found", {status: 404}))));
+
+    const url = "https://pyscript.net/non-existent-page"
+    const expectedError = new FetchError(
+      ErrorCode.FETCH_NOT_FOUND_ERROR,
+      `Fetching from URL ${url} failed with error 404 (Not Found).`
+    )
+
+    expect(() => robustFetch(url)).rejects.toThrow(expectedError);
+  })
+
+  it('receiving a 404 when fetching should throw FetchError with the right errorCode', async () => {
+    global.fetch = jest.fn(() => (Promise.resolve(new Response("Not Found", {status: 404}))));
+
+    const url = "https://pyscript.net/non-existent-page"
+    const expectedError = new FetchError(
+      ErrorCode.FETCH_NOT_FOUND_ERROR,
+      `Fetching from URL ${url} failed with error 404 (Not Found).`
+    )
+
+    expect(() => robustFetch(url)).rejects.toThrow(expectedError);
+  })
+
+  it('receiving a 401 when fetching should throw FetchError with the right errorCode', async () => {
+    global.fetch = jest.fn(() => (Promise.resolve(new Response("", {status: 401}))));
+
+    const url = "https://pyscript.net/protected-page"
+    const expectedError = new FetchError(
+      ErrorCode.FETCH_UNAUTHORIZED_ERROR,
+      `Fetching from URL ${url} failed with error 401 (Unauthorized).`
+    )
+
+    expect(() => robustFetch(url)).rejects.toThrow(expectedError);
+  })
+
+  it('receiving a 403 when fetching should throw FetchError with the right errorCode', async () => {
+    global.fetch = jest.fn(() => (Promise.resolve(new Response("", {status: 403}))));
+
+    const url = "https://pyscript.net/secret-page"
+    const expectedError = new FetchError(
+      ErrorCode.FETCH_FORBIDDEN_ERROR,
+      `Fetching from URL ${url} failed with error 403 (Forbidden).`
+    )
+
+    expect(() => robustFetch(url)).rejects.toThrow(expectedError);
+  })
+
+  it('receiving a 500 when fetching should throw FetchError with the right errorCode', async () => {
+    global.fetch = jest.fn(() => (Promise.resolve(new Response("Not Found", {status: 500}))));
+
+    const url = "https://pyscript.net/protected-page"
+    const expectedError = new FetchError(
+      ErrorCode.FETCH_SERVER_ERROR,
+      `Fetching from URL ${url} failed with error 500 (Internal Server Error).`
+    )
+
+    expect(() => robustFetch(url)).rejects.toThrow(expectedError);
+  })
+
+  it('receiving a 503 when fetching should throw FetchError with the right errorCode', async () => {
+    global.fetch = jest.fn(() => (Promise.resolve(new Response("Not Found", {status: 503}))));
+
+    const url = "https://pyscript.net/protected-page"
+    const expectedError = new FetchError(
+      ErrorCode.FETCH_UNAVAILABLE_ERROR,
+      `Fetching from URL ${url} failed with error 503 (Service Unavailable).`
+    )
+
+    expect(() => robustFetch(url)).rejects.toThrow(expectedError);
+  })
+});