Add Jest test suite for MapTyper class by Copilot · Pull Request #7 · yuletide/maptyper

Copilot · 2026-02-13T18:52:14Z

No test coverage existed for the MapTyper class. Added comprehensive unit tests.

Changes

Test suite: 19 tests covering MapTyper functionality (91% statement coverage)
- Constructor validation and parameter handling
- Async font initialization with callbacks
- Text-to-GeoJSON conversion pipeline
- SVG generation and parsing
- Bounds calculation
Test infrastructure: Jest with Babel transpilation for ES modules
- Mocks for external dependencies (text-to-svg, svg-to-geojson, @turf/buffer)
- Coverage reporting configured
Scripts: npm test, npm run test:watch, npm run test:coverage

Example

// Constructor validation
expect(() => new MapTyper()).toThrow('Font required');
expect(() => new MapTyper(null)).toThrow('Font required');

// Async initialization with callback
const typer = new MapTyper('/fonts/font.ttf', 72, (loaded) => {
  const geojson = loaded.textToFeatures('Hello');
  // Returns GeoJSON FeatureCollection
});

Original prompt

This section details on the original issue you should resolve

<issue_title>add tests</issue_title>
<issue_description></issue_description>

Comments on the Issue (you are @copilot in this section)

Fixes add tests #4

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netlify · 2026-02-13T18:52:20Z

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Co-authored-by: yuletide <58695+yuletide@users.noreply.github.com>

Copilot

Pull request overview

This PR adds comprehensive test coverage for the MapTyper class, which previously had no tests. The test suite includes 19 tests covering constructor validation, async font initialization, text-to-GeoJSON conversion, SVG generation, and bounds calculation. The PR also establishes the test infrastructure using Jest with Babel transpilation for ES modules.

Changes:

Added comprehensive test suite for MapTyper class with 19 tests covering core functionality
Set up Jest testing infrastructure with Babel transpilation for ES module support
Added test scripts (test, test:watch, test:coverage) and configured coverage collection
Updated .gitignore to exclude node_modules and coverage directories

Reviewed changes

Copilot reviewed 3 out of 6 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
src/maptyper.test.js	New test file with 19 tests covering MapTyper constructor, font initialization, text conversion, SVG generation, bounds calculation, and options configuration
package.json	Added Jest 30.x, Babel, and related test dependencies; configured test scripts
jest.config.js	New Jest configuration with jsdom environment, Babel transform, and coverage settings
babel.config.js	New Babel configuration for ES module transpilation in tests
.gitignore	Added node_modules and coverage to ignored files

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Copilot · 2026-02-13T19:36:10Z

src/maptyper.test.js

+      await new Promise((resolve) => setTimeout(resolve, 10));
+
+      expect(callback).toHaveBeenCalledWith(typer);
+    });


The tests do not cover error handling when font loading fails. The MapTyper.initFont method has error handling that rejects the promise with an error message when TextToSVG.load fails (line 56 in maptyper.js: reject('Error loading font ' + err)), but there are no tests that verify this behavior. Add a test case that mocks TextToSVG.load to call the callback with an error and verify that the promise is properly rejected.

Suggested change

});

});

test('should reject when font loading fails', async () => {

// Access the mocked text-to-svg module

const TextToSVG = require('text-to-svg').default;

const loadError = new Error('load failed');

// For this test, make load call its callback with an error

TextToSVG.load.mockImplementationOnce((fontPath, callback) => {

callback(loadError);

});

await expect(MapTyper.initFont('/bad/font.ttf')).rejects.toMatch(

'Error loading font'

);

});

Copilot · 2026-02-13T19:36:10Z

src/maptyper.test.js

+  describe('textToFeatures', () => {
+    test('should convert text to GeoJSON features after font loads', async () => {
+      const typer = new MapTyper('/path/to/font.ttf');
+
+      // Wait for font to load
+      await new Promise((resolve) => setTimeout(resolve, 10));
+
+      const result = typer.textToFeatures('Hello');
+
+      expect(result).toBeDefined();
+      expect(result.type).toBe('FeatureCollection');
+      expect(result.features).toBeInstanceOf(Array);
+    });
+
+    test('should handle empty text', async () => {
+      const typer = new MapTyper('/path/to/font.ttf');
+
+      // Wait for font to load
+      await new Promise((resolve) => setTimeout(resolve, 10));
+
+      const result = typer.textToFeatures('');
+
+      expect(result).toBeDefined();
+      expect(result.type).toBe('FeatureCollection');
+    });
+
+    test('should handle text with whitespace', async () => {
+      const typer = new MapTyper('/path/to/font.ttf');
+
+      // Wait for font to load
+      await new Promise((resolve) => setTimeout(resolve, 10));
+
+      const result = typer.textToFeatures('Hello World');
+
+      expect(result).toBeDefined();
+      expect(result.type).toBe('FeatureCollection');
+    });
+
+    test('should handle special characters', async () => {
+      const typer = new MapTyper('/path/to/font.ttf');
+
+      // Wait for font to load
+      await new Promise((resolve) => setTimeout(resolve, 10));
+
+      const result = typer.textToFeatures('Hello! @#$%');
+
+      expect(result).toBeDefined();
+      expect(result.type).toBe('FeatureCollection');
+    });
+  });


The tests do not cover the scenario where textToFeatures is called before the font is loaded. The MapTyper.textToFeatures method has special handling for this case (lines 102-106 in maptyper.js), logging an error and attempting to return a promise. However, there are no tests that verify this behavior. Add a test that calls textToFeatures immediately after construction (before the font loads) to ensure this edge case is properly handled.

Initial plan

bdb2800

Copilot AI assigned Copilot and yuletide Feb 13, 2026

Copilot started work on behalf of yuletide February 13, 2026 18:52 View session

Copilot AI and others added 2 commits February 13, 2026 18:53

Initial commit - planning test implementation

c0493e6

Co-authored-by: yuletide <58695+yuletide@users.noreply.github.com>

Add comprehensive Jest test suite for MapTyper class

42ed4c3

Co-authored-by: yuletide <58695+yuletide@users.noreply.github.com>

Copilot AI changed the title ~~[WIP] Add tests for the existing codebase~~ Add Jest test suite for MapTyper class Feb 13, 2026

Copilot AI requested a review from yuletide February 13, 2026 18:58

Copilot finished work on behalf of yuletide February 13, 2026 18:58

yuletide requested review from Copilot and removed request for yuletide February 13, 2026 19:31

Copilot started reviewing on behalf of yuletide February 13, 2026 19:32 View session

Copilot AI reviewed Feb 13, 2026

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Add Jest test suite for MapTyper class#7

Add Jest test suite for MapTyper class#7
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-    });
+    });
+    test('should reject when font loading fails', async () => {
+      // Access the mocked text-to-svg module
+      const TextToSVG = require('text-to-svg').default;
+      const loadError = new Error('load failed');
+      // For this test, make load call its callback with an error
+      TextToSVG.load.mockImplementationOnce((fontPath, callback) => {
+        callback(loadError);
+      });
+      await expect(MapTyper.initFont('/bad/font.ttf')).rejects.toMatch(
+        'Error loading font'
+      );
+    });

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