Add example coverage for tracing

Author: dirk

.gitignore

@@ -1,3 +1,5 @@
+.DS_Store
+
 # Executable itself when building locally.
 quickhook
 

README.md

@@ -1,7 +1,7 @@
 # quickhook
 
 ![Build Status](https://github.com/dirk/quickhook/actions/workflows/push.yml/badge.svg)
-![codecov](https://codecov.io/github/dirk/quickhook/branch/main/graph/badge.svg?token=FRMS9TRJ93)
+[![codecov](https://codecov.io/github/dirk/quickhook/branch/main/graph/badge.svg?token=FRMS9TRJ93)](https://app.codecov.io/github/dirk/quickhook)
 
 Quickhook is a Git hook runner designed for speed. It is opinionated where it matters: hooks are executables organized by directory and must exit with a non-zero code on error. Everything else is up to you!
 

hooks/pre_commit_test.go

@@ -16,7 +16,7 @@ import (
 
 func initGitForPreCommit(t *testing.T) test.TempDir {
 	tempDir := test.NewTempDir(t, 1)
-	tempDir.RequireExec("git", "init", "--quiet", ".")
+	tempDir.RequireExec("git", "init", "--initial-branch=main", "--quiet", ".")
 	tempDir.RequireExec("git", "config", "--local", "user.name", "example")
 	tempDir.RequireExec("git", "config", "--local", "user.email", "[email protected]")
 	tempDir.WriteFile([]string{"example.txt"}, "Changed!")
@@ -173,7 +173,7 @@ func TestMutatingCanAccessGit(t *testing.T) {
 		{
 			"stderr",
 			"#!/bin/sh \n git status 1>&2",
-			"accesses-git: On branch master",
+			"accesses-git: On branch main",
 		},
 	}
 	for _, tt := range ptyTests {

tracing/tracing.go

@@ -8,22 +8,22 @@ import (
 type Span struct {
 	name  string
 	start time.Time
-	end   *time.Time
+	end   time.Time
 }
 
 func NewSpan(name string) *Span {
+	start := time.Now()
 	span := &Span{
 		name:  name,
-		start: time.Now(),
-		end:   nil,
+		start: start,
+		end:   start,
 	}
 	spans = append(spans, span)
 	return span
 }
 
 func (span *Span) End() {
-	now := time.Now()
-	span.end = &now
+	span.end = time.Now()
 }
 
 func (span *Span) Elapsed() time.Duration {
@@ -41,7 +41,7 @@ func Start() func() {
 			millis := elapsed.Milliseconds()
 			var human string
 			if millis <= 2 {
-				human = fmt.Sprintf("%dns", elapsed.Microseconds())
+				human = fmt.Sprintf("%dus", elapsed.Microseconds())
 			} else {
 				human = fmt.Sprintf("%dms", millis)
 			}

tracing/tracing_test.go

@@ -0,0 +1,16 @@
+package tracing
+
+import "time"
+
+func ExampleStart() {
+	finish := Start()
+	span := NewSpan("short")
+	span.end = span.start.Add(time.Nanosecond * 12_300)
+	span = NewSpan("long")
+	span.end = span.start.Add(time.Microsecond * 23_400)
+	finish()
+	// Output:
+	// Traced 2 span(s):
+	// short 12us
+	// long 23ms
+}