feat: initial public version

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{}