chore(predicates): add tests

@vates/predicates/index.spec.js

@@ -0,0 +1,65 @@
+'use strict'
+
+const assert = require('assert/strict')
+const { describe, it } = require('tap').mocha
+
+const { every, some } = require('./')
+
+const T = () => true
+const F = () => false
+
+const testArgsHandling = fn => {
+  it('returns undefined if all predicates are undefined', () => {
+    assert.equal(fn(undefined), undefined)
+    assert.equal(fn([undefined]), undefined)
+  })
+
+  it('returns the predicate if only a single one is passed', () => {
+    assert.equal(fn(undefined, T), T)
+    assert.equal(fn([undefined, T]), T)
+  })
+
+  it('throws if it receives a non-predicate', () => {
+    const error = new TypeError('not a valid predicate')
+    error.value = 3
+    assert.throws(() => fn(3), error)
+  })
+
+  it('forwards this and arguments to predicates', () => {
+    const thisArg = 'qux'
+    const args = ['foo', 'bar', 'baz']
+    const predicate = function () {
+      assert.equal(this, thisArg)
+      assert.deepEqual(Array.from(arguments), args)
+    }
+    fn(predicate, predicate).apply(thisArg, args)
+  })
+}
+
+const runTests = (fn, truthTable) =>
+  it('works', () => {
+    truthTable.forEach(([result, ...predicates]) => {
+      assert.equal(fn(...predicates)(), result)
+      assert.equal(fn(predicates)(), result)
+    })
+  })
+
+describe('every', () => {
+  testArgsHandling(every)
+  runTests(every, [
+    [true, T, T],
+    [false, T, F],
+    [false, F, T],
+    [false, F, F],
+  ])
+})
+
+describe('some', () => {
+  testArgsHandling(some)
+  runTests(some, [
+    [true, T, T],
+    [true, T, F],
+    [true, F, T],
+    [false, F, F],
+  ])
+})

@vates/predicates/package.json

@@ -31,6 +31,10 @@
     "node": ">=6"
   },
   "scripts": {
-    "postversion": "npm publish --access public"
+    "postversion": "npm publish --access public",
+    "test": "tap"
+  },
+  "devDependencies": {
+    "tap": "^15.1.6"
   }
 }

package.json

@@ -56,6 +56,7 @@
     ],
     "testEnvironment": "node",
     "testPathIgnorePatterns": [
+      "/@vates/predicates/",
       "/dist/",
       "/xo-server-test/",
       "/xo-web/"