Initial commit.

Author: nathan-osman

.github/workflows/test.yml

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+name: Test
+on: [push, pull_request]
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Install Go
+        uses: actions/setup-go@v5
+        with:
+          go-version: "stable"
+
+      - name: Run test suite
+        run: go test -v -coverprofile=profile.cov ./...
+
+      - name: Coveralls
+        uses: coverallsapp/github-action@v2
+        with:
+          file: profile.cov

LICENSE.txt

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+The MIT License (MIT)
+
+Copyright (c) 2025 Nathan Osman
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

README.md

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+## mocktime
+
+[![Build Status](https://github.com/nitroshare/mocktime/actions/workflows/test.yml/badge.svg)](https://github.com/nitroshare/mocktime/actions/workflows/test.yml)
+[![Coverage Status](https://coveralls.io/repos/github/nitroshare/mocktime/badge.svg?branch=main)](https://coveralls.io/github/nitroshare/mocktime?branch=main)
+[![Go Reference](https://pkg.go.dev/badge/github.com/nitroshare/mocktime.svg)](https://pkg.go.dev/github.com/nitroshare/mocktime)
+[![MIT License](https://img.shields.io/badge/license-MIT-9370d8.svg?style=flat)](https://opensource.org/licenses/MIT)
+
+This package provides an easy way to mock specific functions in the `time` package:
+
+```golang
+import "github.com/nitroshare/mocktime"
+
+// Same as time.Now()
+mocktime.Now()
+
+// Mock Now() and After()
+mocktime.Mock()
+defer mocktime.Unmock()
+
+// All calls to Now() will return the same time...
+mocktime.Now()
+
+// ...until the time is advanced
+mocktime.Advance(5 * time.Second)
+
+// ...or explicitly set
+mocktime.Set(time.Date(2025, time.May, 1, 0, 0, 0, 0, time.UTC))
+
+// Works with After() as well - this example will attempt to wait for five
+// seconds but will only wait one second since the mocked time is advanced ten
+// seconds in the goroutine, triggering the channel send.
+go func() {
+    time.Sleep(1 * time.Second)
+    fmt.Println("Advancing mocked time by 10 seconds")
+    time.Advance(10 * time.Second)
+}()
+fmt.Println("Waiting 5 mocked seconds...")
+<-mocktime.After(5 * time.Second)
+fmt.Println("...time elapsed!")
+```

go.mod

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+module github.com/nitroshare/mocktime
+
+go 1.23.0

mocktime.go

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+package mocktime
+
+import (
+	"time"
+)
+
+type afterChanData struct {
+	expiry time.Time
+	ch     chan<- time.Time
+}
+
+var (
+	mockTime  time.Time
+	afterChan []*afterChanData
+)
+
+// MockNow returns the current mocked time. Although this can be set by
+// reassigning Now, this is typically handled automatically by Mock.
+func MockNow() time.Time {
+	return mockTime
+}
+
+func MockAfter(d time.Duration) <-chan time.Time {
+	ch := make(chan time.Time)
+	afterChan = append(afterChan, &afterChanData{
+		expiry: mockTime.Add(d),
+		ch:     ch,
+	})
+	return ch
+}
+
+// Set explicitly sets the mocked time.
+func Set(t time.Time) {
+	mockTime = t
+	expInd := 0
+	for i, v := range afterChan {
+		if v.expiry.After(mockTime) {
+			expInd = i
+			break
+		}
+		go func() {
+			v.ch <- v.expiry
+		}()
+	}
+	afterChan = afterChan[expInd:]
+}
+
+// Advance advances the mocked time by the specified duration.
+func Advance(d time.Duration) {
+	Set(mockTime.Add(d))
+}
+
+var (
+
+	// Now normally points to time.Now but can also be pointed to with MockNow.
+	Now func() time.Time
+
+	// After normally points to time.After but can also be pointed to with MockAfter.
+	After func(d time.Duration) <-chan time.Time
+)
+
+func set() {
+	Now = MockNow
+	After = MockAfter
+}
+
+func reset() {
+	Now = time.Now
+	After = time.After
+}
+
+func init() {
+	reset()
+}
+
+// Mock replaces the time functions in this package with their mocked equivalents.
+func Mock() {
+	set()
+}
+
+// Unmock replaces the mocked time functions with their original equivalents.
+func Unmock() {
+	reset()
+}

mocktime_test.go

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+package mocktime
+
+import (
+	"testing"
+	"time"
+)
+
+func compare[T comparable](t *testing.T, v1, v2 T, same bool) {
+	t.Helper()
+	if same {
+		if v1 != v2 {
+			t.Fatalf("%v != %v", v1, v2)
+		}
+	} else {
+		if v1 == v2 {
+			t.Fatalf("%v == %v", v1, v2)
+		}
+	}
+}
+
+func TestMockUnmock(t *testing.T) {
+	compare(t, Now(), time.Time{}, false)
+	Mock()
+	compare(t, Now(), time.Time{}, true)
+	Unmock()
+	compare(t, Now(), time.Time{}, false)
+}
+
+func TestSetAdvance(t *testing.T) {
+	Mock()
+	defer Unmock()
+	v := time.Date(2000, time.January, 1, 0, 0, 0, 0, time.UTC)
+	Set(v)
+	compare(t, Now(), v, true)
+	d := 24 * time.Hour
+	Advance(d)
+	compare(t, Now(), v.Add(d), true)
+}
+
+func TestAfter(t *testing.T) {
+	Mock()
+	defer Unmock()
+	ch := After(2 * time.Second)
+	Advance(1 * time.Second)
+	select {
+	case <-ch:
+		t.Fatalf("unexpected read on channel")
+	case <-time.After(10 * time.Millisecond):
+	}
+	Advance(2 * time.Second)
+	select {
+	case <-ch:
+	case <-time.After(10 * time.Millisecond):
+		t.Fatalf("unexpected block on channel")
+	}
+}