Fix faulty TypeScript typings

#229

.github/workflows/nodejs.yml

@@ -26,6 +26,7 @@ jobs:
     - run: npm ci
     - run: npm run lint
     - run: npm run test
+    - run: npm run test:types
     - run: npm run test:build
       env:
         CI: true

exif-reader.d.ts

@@ -53,16 +53,22 @@ interface PngFileTags {
     }
 }
 
+interface PngPhysTags {
+    'Pixels Per Unit X'?: NumberFileTag,
+    'Pixels Per Unit Y'?: NumberFileTag,
+    'Pixel Units'?: {
+        value: number,
+        description: 'meters' | 'Unknown'
+    },
+    'Modify Date'?: NumberArrayFileTag
+}
+
 interface PngTag {
     description: string,
     value: string | number
 }
 
-interface PngTags extends PngFileTags {
-    'Pixels Per Unit X'?: NumberFileTag
-    'Pixels Per Unit Y'?: NumberFileTag
-    'Pixel Units'?: 'meters' | 'Unknown'
-    'Modify Date'?: NumberArrayFileTag
+type PngTags = PngFileTags & PngPhysTags & {
     [name: string]: PngTag
 }
 

package.json

@@ -44,6 +44,7 @@
     "rimraf": "^3.0.2",
     "string-replace-loader": "^3.0.3",
     "terser-webpack-plugin": "^5.2.4",
+    "typescript": "^5.0.2",
     "webpack": "^5.74.0",
     "webpack-cli": "^4.10.0",
     "webpack-dev-server": "^4.11.1"
@@ -60,21 +61,22 @@
     "test:build:custom": "mocha --bail test/build/test-custom.js",
     "test:build:update": "node test/build/update.js",
     "test:e2e": "cypress run",
-    "test:all": "npm-run-all lint coverage test:e2e test:build test:build:custom",
+    "test:types": "tsc --noEmit --project test/types",
+    "test:all": "npm-run-all lint coverage test:e2e test:build test:build:custom test:types",
     "postinstall": "node bin/build.js --only-with-config"
   },
   "nyc": {
     "check-coverage": true,
     "statements": 95,
-    "branches": 93,
+    "branches": 92,
     "functions": 98,
-    "lines": 96,
+    "lines": 95,
     "reporter": [
       "lcov",
       "text"
     ],
     "exclude": [
-      "test/**/*.js",
+      "test/*",
       "**/node_modules/*"
     ]
   },

test/types/exif-reader.ts

@@ -0,0 +1,21 @@
+import {load} from '../../exif-reader.js';
+
+load('', {includeUnknown: true});
+load('', {length: 1024});
+load('', {expanded: false, includeUnknown: true, length: 1024});
+
+const tags = await load('');
+const expandedTags = await load('', {expanded: true});
+
+////////
+// PNG
+tags['Color Type']?.description === 'Grayscale';
+
+expandedTags.png?.['Color Type']?.description === 'Grayscale';
+expandedTags.png?.['Pixel Units']?.value === 1;
+// @ts-expect-error
+expandedTags.png?.['Pixel Units']?.value === 'a string';
+expandedTags.png?.['Pixel Units']?.description === 'meters';
+// @ts-expect-error
+expandedTags.png?.['Color Type']?.description === 'A non-color type value';
+expandedTags.png?.['Custom Tag Name']?.description === 'Should work';

test/types/tsconfig.json

@@ -0,0 +1,8 @@
+{
+    "compilerOptions": {
+      "target": "es2017",
+      "module": "es2022",
+      "strict": true
+    },
+    "include": ["./*.ts"]
+  }

test/unit/png-text-tags-spec.js

@@ -27,4 +27,14 @@ describe('png-text-tags', () => {
             description: 'My other value.'
         });
     });
+
+    it('should ignore tags that use compression', () => {
+        const tagDataiTXt = 'MyTag1\x00\x01\x00fr\x00MyFrTag1\x00Compressed value.';
+        const dataView = getDataView(tagDataiTXt);
+        const chunks = [{type: 'iTXt', offset: 0, length: tagDataiTXt.length}];
+
+        const tags = PngTextTags.read(dataView, chunks);
+
+        expect(tags).to.deep.equal({});
+    });
 });