feat: initial public version

execy/execy.go

@@ -0,0 +1,31 @@
+// Package execy runs external commands.
+package execy
+
+import (
+	"os/exec"
+)
+
+var runner = Runner(&osRunner{})
+
+// Runner executes external commands.
+type Runner interface {
+	Run(cmd *exec.Cmd) error
+}
+
+// osRunner runs OS programs.
+type osRunner struct{}
+
+func (r *osRunner) Run(cmd *exec.Cmd) error {
+	return cmd.Run()
+}
+
+func Run(cmd *exec.Cmd) error {
+	return runner.Run(cmd)
+}
+
+// CmdOut represents the result of the command run.
+type CmdOut struct {
+	Stdout string
+	Stderr string
+	Err    error
+}

execy/execy_test.go

@@ -0,0 +1,29 @@
+package execy
+
+import (
+	"context"
+	"os/exec"
+	"strings"
+	"testing"
+)
+
+func TestRunner(t *testing.T) {
+	const want = "hello world"
+	ctx := context.Background()
+	cmd := exec.CommandContext(ctx, "echo", "-n", want)
+	outb := new(strings.Builder)
+	errb := new(strings.Builder)
+	cmd.Stdout = outb
+	cmd.Stderr = errb
+
+	err := Run(cmd)
+	if err != nil {
+		t.Fatalf("Err: expected nil, got %v", err)
+	}
+	if outb.String() != want {
+		t.Errorf("Stdout: expected %q, got %q", want, outb.String())
+	}
+	if errb.String() != "" {
+		t.Errorf("Stderr: expected %q, got %q", "", errb.String())
+	}
+}

execy/mock.go

@@ -0,0 +1,44 @@
+package execy
+
+import (
+	"os/exec"
+	"strings"
+
+	"github.com/nalgeon/codapi/logx"
+)
+
+// Mock installs mock outputs for given commands.
+func Mock(commands map[string]CmdOut) *logx.Memory {
+	if commands != nil {
+		mockCommands = commands
+	}
+	mem := logx.NewMemory("exec")
+	runner = &mockRunner{mem}
+	return mem
+}
+
+// mockRunner returns mock outputs
+// without running OS programs.
+type mockRunner struct {
+	mem *logx.Memory
+}
+
+// Run returns a mock output from the registry
+// that matches the given command name and argument.
+func (r *mockRunner) Run(cmd *exec.Cmd) error {
+	cmdStr := strings.Join(cmd.Args, " ")
+	r.mem.WriteString(cmdStr)
+
+	key := cmd.Args[0] + " " + cmd.Args[1]
+	out, ok := mockCommands[key]
+	if !ok {
+		// command is not in the registry,
+		// so let's return an empty "success" result
+		out = CmdOut{}
+	}
+	_, _ = cmd.Stdout.Write([]byte(out.Stdout))
+	_, _ = cmd.Stderr.Write([]byte(out.Stderr))
+	return out.Err
+}
+
+var mockCommands map[string]CmdOut = map[string]CmdOut{}

execy/mock_test.go

@@ -0,0 +1,33 @@
+package execy
+
+import (
+	"context"
+	"os/exec"
+	"strings"
+	"testing"
+)
+
+func TestMock(t *testing.T) {
+	const want = "hello world"
+	out := CmdOut{Stdout: want, Stderr: "", Err: nil}
+	mem := Mock(map[string]CmdOut{"echo -n": out})
+
+	ctx := context.Background()
+	cmd := exec.CommandContext(ctx, "echo", "-n", want)
+	outb := new(strings.Builder)
+	errb := new(strings.Builder)
+	cmd.Stdout = outb
+	cmd.Stderr = errb
+
+	err := Run(cmd)
+	if err != nil {
+		t.Fatalf("Err: expected nil, got %v", err)
+	}
+	if outb.String() != want {
+		t.Errorf("Stdout: expected %q, got %q", want, outb.String())
+	}
+	if errb.String() != "" {
+		t.Errorf("Stderr: expected %q, got %q", "", errb.String())
+	}
+	mem.MustHave(t, "echo -n hello world")
+}