Add a util/exec interface for testing execs.

pkg/util/exec/exec_test.go

@@ -0,0 +1,83 @@
+/*
+Copyright 2014 Google Inc. All rights reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package exec
+
+import (
+	"testing"
+)
+
+func TestExecutorNoArgs(t *testing.T) {
+	ex := New()
+
+	cmd := ex.Command("/bin/true")
+	out, err := cmd.CombinedOutput()
+	if err != nil {
+		t.Errorf("expected success, got %+v", err)
+	}
+	if len(out) != 0 {
+		t.Errorf("expected no output, got %q", string(out))
+	}
+
+	cmd = ex.Command("/bin/false")
+	out, err = cmd.CombinedOutput()
+	if err == nil {
+		t.Errorf("expected failure, got nil error")
+	}
+	if len(out) != 0 {
+		t.Errorf("expected no output, got %q", string(out))
+	}
+	ee, ok := err.(ExitError)
+	if !ok {
+		t.Errorf("expected an ExitError, got %+v", err)
+	}
+	if ee.Exited() {
+		if code := ee.ExitStatus(); code != 1 {
+			t.Errorf("expected exit status 1, got %d", code)
+		}
+	}
+
+	cmd = ex.Command("/does/not/exist")
+	out, err = cmd.CombinedOutput()
+	if err == nil {
+		t.Errorf("expected failure, got nil error")
+	}
+	if ee, ok := err.(ExitError); ok {
+		t.Errorf("expected non-ExitError, got %+v", ee)
+	}
+}
+
+func TestExecutorWithArgs(t *testing.T) {
+	ex := New()
+
+	cmd := ex.Command("/bin/echo", "stdout")
+	out, err := cmd.CombinedOutput()
+	if err != nil {
+		t.Errorf("expected success, got %+v", err)
+	}
+	if string(out) != "stdout\n" {
+		t.Errorf("unexpected output: %q", string(out))
+	}
+
+	cmd = ex.Command("/bin/sh", "-c", "echo stderr > /dev/stderr")
+	out, err = cmd.CombinedOutput()
+	if err != nil {
+		t.Errorf("expected success, got %+v", err)
+	}
+	if string(out) != "stderr\n" {
+		t.Errorf("unexpected output: %q", string(out))
+	}
+}