1 files changed, 64 insertions, 0 deletions
diff --git a/date-fns/src/setMilliseconds/test.ts b/date-fns/src/setMilliseconds/test.ts
new file mode 100644
index 0000000..6becea2
--- /dev/null
+++ b/date-fns/src/setMilliseconds/test.ts
@@ -0,0 +1,64 @@
+// @flow
+/* eslint-env mocha */
+
+import assert from 'power-assert'
+import setMilliseconds from '.'
+
+describe('setMilliseconds', function() {
+  it('sets the milliseconds', function() {
+    const result = setMilliseconds(
+      new Date(2014, 8 /* Sep */, 1, 11, 30, 40, 500),
+      300
+    )
+    assert.deepEqual(result, new Date(2014, 8 /* Sep */, 1, 11, 30, 40, 300))
+  })
+
+  it('accepts a timestamp', function() {
+    const result = setMilliseconds(
+      new Date(2014, 8 /* Sep */, 1, 11, 30, 15, 750).getTime(),
+      755
+    )
+    assert.deepEqual(result, new Date(2014, 8 /* Sep */, 1, 11, 30, 15, 755))
+  })
+
+  it('converts a fractional number to an integer', function() {
+    const result = setMilliseconds(
+      new Date(2014, 8 /* Sep */, 1, 11, 30, 40, 500),
+      300.999
+    )
+    assert.deepEqual(result, new Date(2014, 8 /* Sep */, 1, 11, 30, 40, 300))
+  })
+
+  it('implicitly converts number arguments', function() {
+    const result = setMilliseconds(
+      new Date(2014, 8 /* Sep */, 1, 11, 30, 40, 500),
+      // @ts-expect-error
+      '300'
+    )
+    assert.deepEqual(result, new Date(2014, 8 /* Sep */, 1, 11, 30, 40, 300))
+  })
+
+  it('does not mutate the original date', function() {
+    var date = new Date(2014, 8 /* Sep */, 1, 11, 30, 40, 500)
+    setMilliseconds(date, 137)
+    assert.deepEqual(date, new Date(2014, 8 /* Sep */, 1, 11, 30, 40, 500))
+  })
+
+  it('returns `Invalid Date` if the given date is invalid', function() {
+    const result = setMilliseconds(new Date(NaN), 300)
+    assert(result instanceof Date && isNaN(result.getTime()))
+  })
+
+  it('returns `Invalid Date` if the given amount is NaN', function() {
+    const result = setMilliseconds(
+      new Date(2014, 8 /* Sep */, 1, 11, 30, 40, 500),
+      NaN
+    )
+    assert(result instanceof Date && isNaN(result.getTime()))
+  })
+
+  it('throws TypeError exception if passed less than 2 arguments', function() {
+    assert.throws(setMilliseconds.bind(null), TypeError)
+    assert.throws(setMilliseconds.bind(null, 1), TypeError)
+  })
+})