1 files changed, 50 insertions, 0 deletions
diff --git a/date-fns/src/setDayOfYear/test.ts b/date-fns/src/setDayOfYear/test.ts
new file mode 100644
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+++ b/date-fns/src/setDayOfYear/test.ts
@@ -0,0 +1,50 @@
+// @flow
+/* eslint-env mocha */
+
+import assert from 'power-assert'
+import setDayOfYear from '.'
+
+describe('setDayOfYear', function() {
+  it('sets the day of the year', function() {
+    const result = setDayOfYear(new Date(2014, 6 /* Jul */, 2), 2)
+    assert.deepEqual(result, new Date(2014, 0 /* Jan */, 2))
+  })
+
+  it('accepts a timestamp', function() {
+    const result = setDayOfYear(new Date(2014, 6 /* Jul */, 2).getTime(), 60)
+    assert.deepEqual(result, new Date(2014, 2 /* Mar */, 1))
+  })
+
+  it('converts a fractional number to an integer', function() {
+    const result = setDayOfYear(new Date(2014, 6 /* Jul */, 2), 2.75)
+    assert.deepEqual(result, new Date(2014, 0 /* Jan */, 2))
+  })
+
+  it('implicitly converts number arguments', function() {
+    // $ExpectedMistake
+    // @ts-expect-error
+    const result = setDayOfYear(new Date(2014, 6 /* Jul */, 2), '2')
+    assert.deepEqual(result, new Date(2014, 0 /* Jan */, 2))
+  })
+
+  it('does not mutate the original date', function() {
+    const date = new Date(2014, 6 /* Jul */, 2)
+    setDayOfYear(date, 365)
+    assert.deepEqual(date, new Date(2014, 6 /* Jul */, 2))
+  })
+
+  it('returns `Invalid Date` if the given date is invalid', function() {
+    const result = setDayOfYear(new Date(NaN), 2)
+    assert(result instanceof Date && isNaN(result))
+  })
+
+  it('returns `Invalid Date` if the given amount is NaN', function() {
+    const result = setDayOfYear(new Date(2014, 6 /* Jul */, 2), NaN)
+    assert(result instanceof Date && isNaN(result))
+  })
+
+  it('throws TypeError exception if passed less than 2 arguments', function() {
+    assert.throws(setDayOfYear.bind(null), TypeError)
+    assert.throws(setDayOfYear.bind(null, 1), TypeError)
+  })
+})