first commit

pigo/internal/clipboard/clipboard_test.go

@@ -0,0 +1,61 @@
+package clipboard
+
+// Tests for the clipboard helper (US-009, #125). Copy shells out to a platform
+// utility, so we cannot assert the OS clipboard actually changed in a hermetic
+// test. Instead we verify the graceful-degradation contract: with no utility on
+// PATH, Copy returns ErrUnavailable (so the REPL can fall back to printing) and
+// Available reports false. We control the environment by pointing PATH at an
+// empty temp dir.
+
+import (
+	"errors"
+	"os"
+	"testing"
+)
+
+// TestCopyUnavailableWhenNoUtility verifies Copy returns ErrUnavailable and
+// Available returns false when PATH holds no clipboard utility. This is the
+// contract the REPL relies on to degrade to printing.
+func TestCopyUnavailableWhenNoUtility(t *testing.T) {
+	// Point PATH at an empty dir so exec.LookPath finds no pbcopy/xclip/etc.
+	empty := t.TempDir()
+	t.Setenv("PATH", empty)
+
+	if Available() {
+		t.Error("Available() = true with empty PATH, want false")
+	}
+	err := Copy("hello")
+	if !errors.Is(err, ErrUnavailable) {
+		t.Errorf("Copy err = %v, want ErrUnavailable", err)
+	}
+}
+
+// TestCopyUsesUtilityOnPath verifies Copy invokes a discovered utility and
+// succeeds when the utility exits 0. We plant a fake executable named after the
+// current platform's first candidate on PATH and confirm Copy returns nil.
+func TestCopyUsesUtilityOnPath(t *testing.T) {
+	cands := candidates()
+	if len(cands) == 0 {
+		t.Skip("no clipboard candidates for this platform")
+	}
+	dir := t.TempDir()
+	name := cands[0].name
+	if os.PathSeparator == '\\' {
+		t.Skip("fake-executable planting not supported on Windows in this test")
+	}
+	// A trivial script that drains stdin and exits 0, using only shell builtins
+	// (the test empties PATH, so external commands like `cat` are unavailable).
+	script := "#!/bin/sh\nwhile read _; do :; done\nexit 0\n"
+	path := dir + string(os.PathSeparator) + name
+	if err := os.WriteFile(path, []byte(script), 0o755); err != nil {
+		t.Fatalf("write fake %s: %v", name, err)
+	}
+	t.Setenv("PATH", dir)
+
+	if !Available() {
+		t.Fatal("Available() = false after planting fake utility")
+	}
+	if err := Copy("payload"); err != nil {
+		t.Errorf("Copy err = %v, want nil", err)
+	}
+}