Jest lint (#118)

* Jest lint

* Feedback

.eslintrc.json

@@ -72,8 +72,13 @@
             }
         ],
         "@typescript-eslint/require-await": ["error"],
-        "react-hooks/rules-of-hooks": "error",
-        "react-hooks/exhaustive-deps": "error"
+        "jest/expect-expect": ["error", {
+            "assertFunctionNames": [
+                "expect*",
+                "checkImageData",
+                "testCode"
+            ]
+        }]
     },
     "env": {
         "builtin": true,
@@ -86,6 +91,7 @@
     },
     "extends": [
         "eslint:recommended",
+        "plugin:jest/recommended",
         "plugin:react/recommended",
         "plugin:react-hooks/recommended"
     ],

package-lock.json

@@ -32,6 +32,7 @@
         "babel-jest": "^27.2.4",
         "canvas": "^2.8.0",
         "eslint": "^8.16.0",
+        "eslint-plugin-jest": "^26.4.3",
         "eslint-plugin-react": "^7.30.0",
         "eslint-plugin-react-hooks": "^4.5.0",
         "file-loader": "^6.0.0",
@@ -5669,6 +5670,30 @@
         "url": "https://opencollective.com/eslint"
       }
     },
+    "node_modules/eslint-plugin-jest": {
+      "version": "26.4.3",
+      "resolved": "https://registry.npmjs.org/eslint-plugin-jest/-/eslint-plugin-jest-26.4.3.tgz",
+      "integrity": "sha512-eb4sIRLy7hBdBphCBttE1Gx3Go6GsCYXRfy1xtuSg56UBlLLuFpbA79jPipbUfz7AwuDJ+j9UShN7AOi6VDEuQ==",
+      "dev": true,
+      "dependencies": {
+        "@typescript-eslint/utils": "^5.10.0"
+      },
+      "engines": {
+        "node": "^12.22.0 || ^14.17.0 || >=16.0.0"
+      },
+      "peerDependencies": {
+        "@typescript-eslint/eslint-plugin": "^5.0.0",
+        "eslint": "^6.0.0 || ^7.0.0 || ^8.0.0"
+      },
+      "peerDependenciesMeta": {
+        "@typescript-eslint/eslint-plugin": {
+          "optional": true
+        },
+        "jest": {
+          "optional": true
+        }
+      }
+    },
     "node_modules/eslint-plugin-react": {
       "version": "7.30.0",
       "resolved": "https://registry.npmjs.org/eslint-plugin-react/-/eslint-plugin-react-7.30.0.tgz",
@@ -18916,6 +18941,15 @@
         }
       }
     },
+    "eslint-plugin-jest": {
+      "version": "26.4.3",
+      "resolved": "https://registry.npmjs.org/eslint-plugin-jest/-/eslint-plugin-jest-26.4.3.tgz",
+      "integrity": "sha512-eb4sIRLy7hBdBphCBttE1Gx3Go6GsCYXRfy1xtuSg56UBlLLuFpbA79jPipbUfz7AwuDJ+j9UShN7AOi6VDEuQ==",
+      "dev": true,
+      "requires": {
+        "@typescript-eslint/utils": "^5.10.0"
+      }
+    },
     "eslint-plugin-react": {
       "version": "7.30.0",
       "resolved": "https://registry.npmjs.org/eslint-plugin-react/-/eslint-plugin-react-7.30.0.tgz",

package.json

@@ -41,6 +41,7 @@
     "babel-jest": "^27.2.4",
     "canvas": "^2.8.0",
     "eslint": "^8.16.0",
+    "eslint-plugin-jest": "^26.4.3",
     "eslint-plugin-react": "^7.30.0",
     "eslint-plugin-react-hooks": "^4.5.0",
     "file-loader": "^6.0.0",

test/components/FileChooser.spec.tsx

@@ -2,7 +2,6 @@
  * @jest-environment ./test/env/jsdom-with-backdoors
  */
 
-import 'jest';
 import { h } from 'preact';
 import { fireEvent, render, screen, waitFor } from '@testing-library/preact';
 
@@ -79,7 +78,9 @@ describe('FileChooser', () => {
         const mockFilePicker = jest.fn<ReturnType<ShowOpenFilePicker>, Parameters<ShowOpenFilePicker>>();
 
         beforeEach(() => {
-            expect(window.showOpenFilePicker).not.toBeDefined();
+            if (typeof window.showOpenFilePicker !== 'undefined') {
+                throw new Error('window.showOpenFilePicker not undefined');
+            }
             window.showOpenFilePicker = mockFilePicker as unknown as ShowOpenFilePicker;
             mockFilePicker.mockReset();
         });
@@ -126,4 +127,4 @@ describe('FileChooser', () => {
             });
         });
     });
-});
+});

test/js/formats/util.ts

@@ -7,7 +7,7 @@ export function skipGap(track: memory, start: number = 0): number {
         i++;
     }
     if (i === end) {
-        fail(`found more than 0x100 0xFF bytes after ${start}`);
+        throw new Error(`found more than 0x100 0xFF bytes after ${start}`);
     }
     return i;
 }
@@ -24,7 +24,7 @@ export function compareSequences(track: memory, bytes: number[], pos: number): b
 export function expectSequence(track: memory, pos: number, bytes: number[]): number {
     if (!compareSequences(track, bytes, pos)) {
         const track_slice = track.slice(pos, Math.min(track.length, pos + bytes.length));
-        fail(`expected ${bytes} got ${track_slice}`);
+        throw new Error(`expected ${bytes} got ${track_slice}`);
     }
     return pos + bytes.length;
 }

test/js/rom.test.ts

@@ -18,7 +18,7 @@ const roms: { [name: string]: { new(): ROM } } = {
 for (const rom of Object.keys(roms)) {
     describe(`${rom}`, () => {
         it('is constructable', () => {
-            new roms[rom]();
+            expect(new roms[rom]()).not.toBeNull();
         });
     });
 }

test/js/util.test.ts

@@ -25,16 +25,17 @@ describe('allocMem', () => {
     });
     it('has garbage in the right places', () => {
         const memory = allocMem(0x800);
+        let passed = false;
         for (let i = 0; i < 0x800; i += 0x200) {
-            const passed = memory[i + 0x28] !== 0xff
+            passed = memory[i + 0x28] !== 0xff
                 && memory[i + 0x29] !== 0xff
                 && memory[i + 0x68] !== 0xff
                 && memory[i + 0x69] !== 0xff;
             if (passed) {
-                return;
+                break;
             }
         }
-        fail('garbage not found');
+        expect(passed).toBe(true);
     });
 });