Add tests for helpers readSettings by TonyBrobston · Pull Request #378 · neilenns/node-deepstackai-trigger

TonyBrobston · 2020-10-09T17:53:37Z

Fixes #371

Description of changes

In general, I try my best to create small, functional, concise pull requests. I wrote tests to cover all of the current functionality in helpers readSettings. This pull request will serve as a good base to create a follow up pull request adding mustache templating. This pull request will also serve as a safety net, when I add mustache templating, these tests should be unmodified and should still pass.

Let me know what you think of this, I'm definitely open to feedback.

Checklist

TonyBrobston · 2020-10-09T17:58:09Z

+import {closeSync, existsSync, openSync, unlinkSync, writeFileSync} from 'fs';
+import * as JSONC from "jsonc-parser";
+import * as helpers from "./../src/helpers";
+
+describe("helpers", () => {
+  const settingsFilePath = `${__dirname}/settings.json`;
+
+  beforeEach(() => {
+    closeSync(openSync(settingsFilePath, 'w'));
+  });
+
+  afterEach(() => {
+    jest.clearAllMocks();
+    if (existsSync(settingsFilePath)) {
+      unlinkSync(settingsFilePath);
+    }
+  });
+
+   test("Verify can load settings.json", () => {
+     const serviceName = "Settings";
+     const expectedSettings = {"foo": "bar"};
+     writeFileSync(settingsFilePath, JSON.stringify(expectedSettings));
+
+     const actualSettings = helpers.readSettings(serviceName, settingsFilePath);
+
+     expect(actualSettings).toEqual(expectedSettings);
+   });
+
+   test("Verify cannot load settings.json because it does not exist", () => {
+     //eslint-disable-next-line no-console
+     console.log = jest.fn();
+     const serviceName = "Settings";
+     unlinkSync(settingsFilePath);
+
+     const actualSettings = helpers.readSettings(serviceName, settingsFilePath);
+
+     //eslint-disable-next-line no-console
+     expect(console.log).toHaveBeenCalledWith(expect.stringContaining("[Settings] Unable to read the configuration file: ENOENT: no such file or directory"));
+     expect(actualSettings).toBeNull();
+   });
+
+   test("Verify throws if rawConfig empty", () => {
+     const serviceName = "Settings";
+     const expectedSettings = "";
+     writeFileSync(settingsFilePath, expectedSettings);
+
+     expect(() => {helpers.readSettings(serviceName, settingsFilePath)}).toThrow(Error);
+   });
+
+   test("Verify throws with message if rawConfig empty", () => {
+     const serviceName = "Settings";
+     const expectedSettings = "";
+     writeFileSync(settingsFilePath, expectedSettings);
+
+     try {
+       helpers.readSettings(serviceName, settingsFilePath);
+     } catch (error) {
+       expect(error.message).toBe(`[${serviceName}] Unable to load configuration file ${settingsFilePath}.`);
+     }
+   });
+
+  test("Verify throws if json invalid", () => {
+    const serviceName = "Settings";
+    const expectedSettings = {};
+    writeFileSync(settingsFilePath, JSON.stringify(expectedSettings));
+    const mockAddListener = jest.spyOn(JSONC, 'parse');
+    mockAddListener.mockImplementation((rawConfig, parseErrors) => {
+        parseErrors.push({
+            error: 1,
+            offset: 2,
+            length: 3,
+        });
+        return {};
+    });
+
+    expect(() => {helpers.readSettings(serviceName, settingsFilePath)}).toThrow(Error);
+  });
+
+  test("Verify throws with message if json invalid", () => {
+    const serviceName = "Settings";
+    const expectedSettings = {};
+    writeFileSync(settingsFilePath, JSON.stringify(expectedSettings));
+    const mockAddListener = jest.spyOn(JSONC, 'parse');
+    mockAddListener.mockImplementation((rawConfig, parseErrors) => {
+        parseErrors = [{
+            error: 1,
+            offset: 2,
+            length: 3,
+        }];
+        return {};
+    });
+    //eslint-disable-next-line no-console
+    console.log = jest.fn();
+
+     try {
+       helpers.readSettings(serviceName, settingsFilePath);
+     } catch (error) {
+       //eslint-disable-next-line no-console
+       expect(console.log).toHaveBeenCalledWith(expect.stringContaining("[Settings] 1"));
+       expect(error.message).toBe(`[${serviceName}] Unable to load configuration file: `);
+     }
+  });
+});


I based a lot of this testing on some previous work I did here: https://github.com/TonyBrobston/logs-to-mqtt-publisher/blob/master/tests/index.test.ts

However, I did my best to follow the current code style of the repo.

Do you have the Prettier extension installed in VSCode? That'll make sure the style matches everything else automatically.

I'm developing in vim.

Also I really just meant like, test vs. it, test naming convention, test file naming convention, etc.

Ah good old vim. I used to have a vi reference coffee mug.

Can you please run npm run format then and push any test files that get changed? Thanks!

The next time I'm in front of my computer I'll do this 🙂.

@danecreekphotography Ok, I ran that.

TonyBrobston · 2020-10-09T19:07:01Z

+        parseErrors.push({
+            error: 1,
+            offset: 2,
+            length: 3,
+        });


I tried:

parseErrors = [{ error: 1, offset: 2, length: 3, }]

but it seems like parseErrors is readonly or something... as I would console.log(parseErrors) and it would output undefined.

TonyBrobston · 2020-10-09T19:07:35Z

  }

-  let parseErrors: JSONC.ParseError[];
+  const parseErrors: JSONC.ParseError[] = [];


This was needed because of https://github.com/danecreekphotography/node-deepstackai-trigger/pull/378/files#r502622394

I wanted to leave this alone, as I'm not sure what will happen at run time of the actual application.

TonyBrobston · 2020-10-09T19:16:12Z

+   test("Verify throws if rawConfig empty", () => {
+     const serviceName = "Settings";
+     const expectedSettings = "";
+     writeFileSync(settingsFilePath, expectedSettings);
+
+     expect(() => {helpers.readSettings(serviceName, settingsFilePath)}).toThrow(Error);
+   });
+
+   test("Verify throws with message if rawConfig empty", () => {
+     const serviceName = "Settings";
+     const expectedSettings = "";
+     writeFileSync(settingsFilePath, expectedSettings);
+
+     try {
+       helpers.readSettings(serviceName, settingsFilePath);
+     } catch (error) {
+       expect(error.message).toBe(`[${serviceName}] Unable to load configuration file ${settingsFilePath}.`);
+     }
+   });


To clarify a bit here. I write two tests, where one makes for sure that the function threw and the other tests the error message. If I deleted the first of the two and left the second, it's possible that the function does not throw and it goes unnoticed because it wouldn't go into the catch and no assertions is considered a successful test, making it a false-positive.

TonyBrobston · 2020-10-09T19:22:59Z

Alright, I think I'm mostly done making changes.

Lmk if you have any other feedback.

Once we get this merged I'll start to think about what implementing mustache templates will look like. Probably something like:

test("Verify can load settings.json", () => {
  const serviceName = "Settings";
  const secrets = {"someSecret": "bar"};
  writeFileSync(secretsFilePath, JSON.stringify(secrets));
  const settings = {"foo": "{{secret.someSecret}}"};
  writeFileSync(settingsFilePath, JSON.stringify(settings));

  const actualSettings = helpers.readSettings(serviceName, settingsFilePath, secretsFilePath);

  expect(actualSettings).toEqual({"foo": "bar"});
});

Also it looks like I will have to modify all the callers of helpers readSettings, since we'll probably pass secretsFilePath in, just like we do with settingsFilePath.

neilenns · 2020-10-11T15:25:12Z

Insert heavy sigh here, looks like my npm run format command doesn't actually touch the tests directory. I'll take care of the formatting in a separate pull request.

TonyBrobston · 2020-10-13T18:42:38Z

@danecreekphotography Are you familiar with Hacktoberfest? Would you mind adding a label of hacktoberfest-accepted to this PR? (since it was accepted and merged) You could also add hacktoberfest as a topic for the entire repo.

Details here on why this is needed this year: https://hacktoberfest.digitalocean.com/hacktoberfest-update
More details on Hacktoberfest: https://hacktoberfest.digitalocean.com/

neilenns · 2020-10-13T19:16:23Z

I added the label to the PR!