From df3f97310fdf69f3514ae89a912e165cf56d9613 Mon Sep 17 00:00:00 2001
From: Sridhar Ratnakumar <sridharr@activestate.com>
Date: Sat, 13 Oct 2012 11:44:47 -0700
Subject: [PATCH] test: fixture workflow to make test functions concise

---
 Makefile     |  3 +++
 tail.go      |  2 +-
 tail_test.go | 75 +++++++++++++++++++++++++++++++---------------------
 watch.go     |  4 +--
 4 files changed, 51 insertions(+), 33 deletions(-)

diff --git a/Makefile b/Makefile
index f5cc885..82328bb 100644
--- a/Makefile
+++ b/Makefile
@@ -2,3 +2,6 @@ default:	test
 
 test:	*.go
 	GOPATH=~/as/logyard go test -v
+
+fmt:
+	go fmt .
diff --git a/tail.go b/tail.go
index 6ca0a66..c807d16 100644
--- a/tail.go
+++ b/tail.go
@@ -1,8 +1,8 @@
 package tail
 
 import (
-	"fmt"
 	"bufio"
+	"fmt"
 	"io"
 	"launchpad.net/tomb"
 	"log"
diff --git a/tail_test.go b/tail_test.go
index b69af5a..a23307b 100644
--- a/tail_test.go
+++ b/tail_test.go
@@ -1,11 +1,11 @@
 package tail
 
 import (
+	_ "fmt"
+	"io/ioutil"
+	"os"
 	"testing"
 	"time"
-	"os"
-	"io/ioutil"
-	_ "fmt"
 )
 
 func init() {
@@ -35,55 +35,70 @@ func TestMissingFile(t *testing.T) {
 }
 
 func TestLocationMinusOne(t *testing.T) {
-	fix := NewFixture("simple")
-	err := ioutil.WriteFile(fix.path + "/test.txt", []byte("hello\nworld\n"), 0777)
-	if err != nil {
-		t.Error(err)
-	}
-	tail, err := TailFile(fix.path + "/test.txt", Config{Follow: true, Location: -1})
-	if err != nil {
-		t.Error(err)
-	}
-	go CompareTailWithLines(t, tail, []string{"hello", "world"})
+	fix := NewFixture("simple", t)
+	fix.CreateFile("test.txt", "hello\nworld\n")
+	tail := fix.StartTail("test.txt", Config{Follow: true, Location: -1})
+	go fix.VerifyTail(tail, []string{"hello", "world"})
 
-	// delete after 1 second, to give tail sufficient time to read all lines.
-	<-time.After(1 * time.Second)
-	err = os.Remove(fix.path + "/test.txt")
-	if err != nil {
-		t.Error(err)
-	}
+	// Delete after a reasonable delay, to give tail sufficient time
+	// to read all lines.
+	<-time.After(250 * time.Millisecond)
+	fix.RemoveFile("test.txt")
 	tail.Stop()
 }
 
 type Fixture struct {
 	Name string
 	path string
+	t    *testing.T
 }
 
-func NewFixture(name string) Fixture {
-	fix := Fixture{name, ".test/" + name}
-	os.MkdirAll(fix.path, os.ModeTemporary | 0700)
+func NewFixture(name string, t *testing.T) Fixture {
+	fix := Fixture{name, ".test/" + name, t}
+	err := os.MkdirAll(fix.path, os.ModeTemporary|0700)
+	if err != nil {
+		t.Fatal(err)
+	}
 	return fix
 }
 
-func CompareTailWithLines(t *testing.T, tail *Tail, lines []string) {
+func (fix Fixture) CreateFile(name string, contents string) {
+	err := ioutil.WriteFile(fix.path+"/"+name, []byte(contents), 0777)
+	if err != nil {
+		fix.t.Fatal(err)
+	}
+}
+
+func (fix Fixture) RemoveFile(name string) {
+	err := os.Remove(fix.path + "/" + name)
+	if err != nil {
+		fix.t.Fatal(err)
+	}
+}
+
+func (fix Fixture) StartTail(name string, config Config) *Tail {
+	tail, err := TailFile(fix.path+"/"+name, config)
+	if err != nil {
+		fix.t.Fatal(err)
+	}
+	return tail
+}
+
+func (fix Fixture) VerifyTail(tail *Tail, lines []string) {
 	for _, line := range lines {
 		tailedLine, ok := <-tail.Lines
 		if !ok {
-			t.Error("insufficient lines from tail")
-			return
+			fix.t.Fatal("insufficient lines from tail")
 		}
 		if tailedLine == nil {
-			t.Errorf("tail.Lines returned nil; not possible")
-			return
+			fix.t.Fatalf("tail.Lines returned nil; not possible")
 		}
 		if tailedLine.Text != line {
-			t.Errorf("mismatch; %s != %s", tailedLine.Text, line)
-			return
+			fix.t.Fatalf("mismatch; %s != %s", tailedLine.Text, line)
 		}
 	}
 	line, ok := <-tail.Lines
 	if ok {
-		t.Errorf("more content from tail: %s", line.Text)
+		fix.t.Fatalf("more content from tail: %s", line.Text)
 	}
 }
diff --git a/watch.go b/watch.go
index dea369d..4e6f30e 100644
--- a/watch.go
+++ b/watch.go
@@ -121,11 +121,11 @@ func (fw *PollingFileWatcher) ChangeEvents() chan bool {
 			if err != nil {
 				if os.IsNotExist(err) {
 					// below goroutine (every2Seconds) will catch up eventually and stop us.
-					continue 
+					continue
 				}
 				panic(err)
 			}
-			
+
 			modTime := fi.ModTime()
 			if modTime != prevModTime {
 				prevModTime = modTime