Use file in os.TempDir() for tests.

Sometimes it's best to not create files in the directories where code lives...
for example, that directory might be read-only, or folks might be using
source-control or build systems that disallow that behavior.  To fix this, we
create a file in the temp directory and use it instead.

We don't use ioutil.TempFile(), since that actually creates the file, and we'd
like the tests to run as if the file had never existed.  We use 16 bytes from
crypto/rand to avoid people doing bad things with symlinks in the temp
directory.

sqlite3_test.go

@@ -1,18 +1,28 @@
 package sqlite
 
 import (
+	"crypto/rand"
 	"database/sql"
+	"encoding/hex"
 	"os"
+	"path/filepath"
 	"testing"
 	"time"
 )
 
+func TempFilename() string {
+	randBytes := make([]byte, 16)
+	rand.Read(randBytes)
+	return filepath.Join(os.TempDir(), "foo"+hex.EncodeToString(randBytes)+".db")
+}
+
 func TestOpen(t *testing.T) {
-	db, err := sql.Open("sqlite3", "./foo.db")
+	tempFilename := TempFilename()
+	db, err := sql.Open("sqlite3", tempFilename)
 	if err != nil {
 		t.Fatal("Failed to open database:", err)
 	}
-	defer os.Remove("./foo.db")
+	defer os.Remove(tempFilename)
 	defer db.Close()
 
 	_, err = db.Exec("drop table foo")
@@ -21,17 +31,18 @@ func TestOpen(t *testing.T) {
 		t.Fatal("Failed to create table:", err)
 	}
 
-	if stat, err := os.Stat("./foo.db"); err != nil || stat.IsDir() {
+	if stat, err := os.Stat(tempFilename); err != nil || stat.IsDir() {
 		t.Error("Failed to create ./foo.db")
 	}
 }
 
 func TestInsert(t *testing.T) {
-	db, err := sql.Open("sqlite3", "./foo.db")
+	tempFilename := TempFilename()
+	db, err := sql.Open("sqlite3", tempFilename)
 	if err != nil {
 		t.Fatal("Failed to open database:", err)
 	}
-	defer os.Remove("./foo.db")
+	defer os.Remove(tempFilename)
 	defer db.Close()
 
 	_, err = db.Exec("drop table foo")
@@ -65,11 +76,12 @@ func TestInsert(t *testing.T) {
 }
 
 func TestUpdate(t *testing.T) {
-	db, err := sql.Open("sqlite3", "./foo.db")
+	tempFilename := TempFilename()
+	db, err := sql.Open("sqlite3", tempFilename)
 	if err != nil {
 		t.Fatal("Failed to open database:", err)
 	}
-	defer os.Remove("./foo.db")
+	defer os.Remove(tempFilename)
 	defer db.Close()
 
 	_, err = db.Exec("drop table foo")
@@ -129,11 +141,12 @@ func TestUpdate(t *testing.T) {
 }
 
 func TestDelete(t *testing.T) {
-	db, err := sql.Open("sqlite3", "./foo.db")
+	tempFilename := TempFilename()
+	db, err := sql.Open("sqlite3", tempFilename)
 	if err != nil {
 		t.Fatal("Failed to open database:", err)
 	}
-	defer os.Remove("./foo.db")
+	defer os.Remove(tempFilename)
 	defer db.Close()
 
 	_, err = db.Exec("drop table foo")
@@ -189,11 +202,12 @@ func TestDelete(t *testing.T) {
 }
 
 func TestBooleanRoundtrip(t *testing.T) {
-	db, err := sql.Open("sqlite3", "./foo.db")
+	tempFilename := TempFilename()
+	db, err := sql.Open("sqlite3", tempFilename)
 	if err != nil {
 		t.Fatal("Failed to open database:", err)
 	}
-	defer os.Remove("./foo.db")
+	defer os.Remove(tempFilename)
 	defer db.Close()
 
 	_, err = db.Exec("DROP TABLE foo")
@@ -237,11 +251,12 @@ func TestBooleanRoundtrip(t *testing.T) {
 }
 
 func TestTimestamp(t *testing.T) {
-	db, err := sql.Open("sqlite3", "./foo.db")
+	tempFilename := TempFilename()
+	db, err := sql.Open("sqlite3", tempFilename)
 	if err != nil {
 		t.Fatal("Failed to open database:", err)
 	}
-	defer os.Remove("./foo.db")
+	defer os.Remove(tempFilename)
 	defer db.Close()
 
 	_, err = db.Exec("DROP TABLE foo")
@@ -318,12 +333,13 @@ func TestTimestamp(t *testing.T) {
 }
 
 func TestBoolean(t *testing.T) {
-	db, err := sql.Open("sqlite3", "./foo.db")
+	tempFilename := TempFilename()
+	db, err := sql.Open("sqlite3", tempFilename)
 	if err != nil {
 		t.Fatal("Failed to open database:", err)
 	}
 
-	defer os.Remove("./foo.db")
+	defer os.Remove(tempFilename)
 	defer db.Close()
 
 	_, err = db.Exec("CREATE TABLE foo(id INTEGER, fbool BOOLEAN)")
@@ -407,4 +423,3 @@ func TestBoolean(t *testing.T) {
 		t.Error("Expected error from \"nonsense\" bool")
 	}
 }
-