feat(*): add and() function that acts as a && operator for controls

Author: niklashigi

src/core/and.spec.ts

@@ -0,0 +1,38 @@
+import { expect } from 'chai'
+import * as Mocha from 'mocha'
+import { and } from './and'
+import { Control } from './control'
+
+describe('The `and()` chaining function', () => {
+
+  const controlA: Control<boolean> = {
+    label: '[A]',
+    icons: ['a'],
+    query: () => false,
+  }
+
+  const controlB: Control<boolean> = {
+    label: '[B]',
+    icons: ['b'],
+    query: () => true,
+  }
+
+  const control = and(controlA, controlB)
+
+  it('correctly combines labels', () => {
+    expect(control.label).to.equal('[A] + [B]')
+  })
+
+  it('correctly combines icons', () => {
+    expect(control.icons).to.deep.equal(['a', 'plus', 'b'])
+  })
+
+  it('makes the combined query work as expected', () => {
+    expect(control.query()).to.equal(false)
+  })
+
+  it('throws an error when less than two controls are specified', () => {
+    expect(() => and(controlA)).to.throw(Error, 'Less than two controls specified!')
+  })
+
+})

src/core/and.ts

@@ -0,0 +1,18 @@
+import { Control } from './control'
+
+export function and(...controls: Array<Control<boolean>>): Control<boolean> {
+  if (controls.length < 2) throw new Error('Less than two controls specified!')
+
+  return {
+    label: controls.map(control => control.label).join(' + '),
+    icons: [].concat(...controls.map(control => control.icons)).join('?plus?').split('?'),
+    query: () => {
+      for (const control of controls) {
+        /* istanbul ignore else */
+        if (!control.query()) return false
+      }
+        /* istanbul ignore next */
+      return true
+    },
+  }
+}

src/index.ts

@@ -1,3 +1,5 @@
 export { Mouse } from './inputs/mouse'
 export { Keyboard } from './inputs/keyboard'
 export { Gamepad } from './inputs/gamepad'
+
+export { and } from './core/and'