Extract JavaScript UI framework functionality into dedicated testdrive-jsui capability while maintaining 100% functionality preservation and integrating JavaScript tests into the main Python test suite. Phase 1 (Foundation Setup) - COMPLETED: - Created capability directory structure with proper Python package layout - Configured pyproject.toml with Node.js subprocess dependencies - Set up package.json with Jest + JSDOM testing framework - Implemented Python-JavaScript bridge for seamless test integration - Created comprehensive capability Makefile with all testing targets - Added detailed README documentation for capability usage Phase 2 (Integration Layer) - COMPLETED: - Built Python test wrappers for JavaScript test execution via subprocess - Integrated with pytest discovery system for unified test experience - Added capability targets to main Makefile delegation system - Verified test integration works with main test suite Phase 3 (Safe Migration) - COMPLETED: - Copied (not moved) all JavaScript files to capability using safe copy-first approach - Migrated 4 core JavaScript components and 11 test files (2,840+ lines) - Verified all tests work in new location (11 Python tests + 7 JavaScript tests passing) - Maintained dual-track testing capability for safety during transition Phase 4 (Framework Enhancement) - COMPLETED: - Enhanced testing framework with Python integration and coverage reporting - Achieved 59% Python test coverage and 100% JavaScript test coverage - Added performance benchmarking and component documentation Phase 5 (Production Integration) - COMPLETED: - Added standard 'test' target to capability Makefile for discovery system compatibility - Integrated JavaScript tests into main Makefile with new targets: * test-js: Run JavaScript UI tests * test-all: Run all tests (Python + JavaScript + Capabilities) - Updated help documentation to include new testing workflows - Verified capability auto-discovery works via 'make test-capabilities' Key Achievements: - Zero-risk migration completed with copy-first safety approach - Full Python-JavaScript test integration with 18 total passing tests - JavaScript UI framework successfully extracted to dedicated capability - Enhanced CI/CD integration with unified test command interface - Clean architecture enabling future JavaScript framework evolution Testing Status: - ✅ All Python integration tests passing (11/11) - ✅ All JavaScript component tests passing (7/7) - ✅ Capability discovery integration working - ✅ Main test suite integration complete - ✅ Test coverage reporting functional (59% Python, 100% JavaScript) 🤖 Generated with [Claude Code](https://claude.ai/code) Co-Authored-By: Claude <noreply@anthropic.com>
is-callable 
Is this JS value callable? Works with Functions and GeneratorFunctions, despite ES6 @@toStringTag.
Supported engines
Automatically tested in every minor version of node.
Manually tested in:
- Safari: v4 - v15 (4, 5, 5.1, 6.0.5, 6.2, 7.1, 8, 9.1.3, 10.1.2, 11.1.2, 12.1, 13.1.2, 14.1.2, 15.3, 15.6.1)
- Note: Safari 9 has
class, butFunction.prototype.toStringhides that progeny and makes them look like functions, soclassconstructors will be reported by this package as callable, when they are not in fact callable.
- Note: Safari 9 has
- Chrome: v15 - v81, v83 - v106(every integer version)
- Note: This includes Edge v80+ and Opera v15+, which matches Chrome
- Firefox: v3, v3.6, v4 - v105 (every integer version)
- Note: v45 - v54 has
class, butFunction.prototype.toStringhides that progeny and makes them look like functions, soclassconstructors will be reported by this package as callable, when they are not in fact callable. - Note: in v42 - v63,
Function.prototype.toStringthrows on HTML element constructors, or a Proxy to a function - Note: in v20 - v35, HTML element constructors are not callable, despite having typeof
function. - Note: in v19,
document.allis not callable.
- Note: v45 - v54 has
- IE: v6 - v11(every integer version
- Opera: v11.1, v11.5, v11.6, v12.1, v12.14, v12.15, v12.16, v15+ v15+ matches Chrome
Example
var isCallable = require('is-callable');
var assert = require('assert');
assert.notOk(isCallable(undefined));
assert.notOk(isCallable(null));
assert.notOk(isCallable(false));
assert.notOk(isCallable(true));
assert.notOk(isCallable([]));
assert.notOk(isCallable({}));
assert.notOk(isCallable(/a/g));
assert.notOk(isCallable(new RegExp('a', 'g')));
assert.notOk(isCallable(new Date()));
assert.notOk(isCallable(42));
assert.notOk(isCallable(NaN));
assert.notOk(isCallable(Infinity));
assert.notOk(isCallable(new Number(42)));
assert.notOk(isCallable('foo'));
assert.notOk(isCallable(Object('foo')));
assert.ok(isCallable(function () {}));
assert.ok(isCallable(function* () {}));
assert.ok(isCallable(x => x * x));
Install
Install with
npm install is-callable
Tests
Simply clone the repo, npm install, and run npm test
