pkg: add test cases for ** in file patterns or globs

Right now we follow the Go semantics, where it is interpreted as two
`*` symbols next to each other, thus behaving like a single star symbol
as the second one will never match anything.

The following commit will change this behavior, to be shown in the
changes made to these added test cases.

Signed-off-by: Daniel Martí <[email protected]>
Change-Id: I521e896c7349f0320bbe5afc63c45b78a7d8a9eb
Reviewed-on: https://review.gerrithub.io/c/cue-lang/cue/+/1198635
TryBot-Result: CUEcueckoo <[email protected]>
Reviewed-by: Roger Peppe <[email protected]>
Unity-Result: CUE porcuepine <[email protected]>

Author: mvdan

pkg/path/match_test.go

@@ -86,6 +86,12 @@ var matchTests = []MatchTest{
 	{"a[", "x", false, ErrBadPattern},
 	{"a/b[", "x", false, ErrBadPattern},
 	{"*x", "xxx", true, nil},
+	// TODO(mvdan): this should fail; right now "**" happens to behave like "*".
+	{"**", "ab/c", false, nil},
+	{"**/c", "ab/c", true, nil},
+	{"a/b/**", "", false, nil},
+	{"\\**", "*ab", true, nil},
+	{"[x**y]", "*", true, nil},
 }
 
 func errp(e error) string {

pkg/tool/file/file_test.go

@@ -19,13 +19,15 @@ import (
 	"os"
 	"path/filepath"
 	"reflect"
+	"runtime"
 	"testing"
 
 	"cuelang.org/go/cue"
 	"cuelang.org/go/cue/parser"
 	"cuelang.org/go/internal/task"
 	"cuelang.org/go/internal/value"
 	"cuelang.org/go/pkg/internal"
+	"github.com/go-quicktest/qt"
 )
 
 func parse(t *testing.T, kind, expr string) cue.Value {
@@ -114,15 +116,47 @@ func TestCreate(t *testing.T) {
 }
 
 func TestGlob(t *testing.T) {
+	// Simple globbing against testdata.
 	v := parse(t, "tool/file.Glob", `{
 		glob: "testdata/input.*"
 	}`)
 	got, err := (*cmdGlob).Run(nil, &task.Context{Obj: v})
-	if err != nil {
-		t.Fatal(err)
+	qt.Assert(t, qt.IsNil(err))
+	qt.Assert(t, qt.DeepEquals(got, any(map[string]any{"files": []string{"testdata/input.foo"}})))
+
+	// globstar or recursive globbing is not supported.
+	// TODO(mvdan): this should fail; right now "**" happens to behave like "*".
+	v = parse(t, "tool/file.Glob", `{
+		glob: "testdata/**/glob.leaf"
+	}`)
+	got, err = (*cmdGlob).Run(nil, &task.Context{Obj: v})
+	qt.Assert(t, qt.IsNil(err))
+	qt.Assert(t, qt.DeepEquals(got, any(map[string]any{"files": []string{"testdata/glob1/glob.leaf"}})))
+}
+
+func TestGlobEscapeStar(t *testing.T) {
+	// `\**` is disallowed in a pattern on Windows, as the backslash is a path separator,
+	// hence `**` is treated as a globstar which is not yet supported.
+	// `\**` is allowed on other OSes as the first star is escaped, and only the second
+	// is treated as a wildcard. Thus such a pattern should match a file like `*.test`.
+	dir := t.TempDir()
+	leafFile := filepath.Join(dir, "*.test")
+	if runtime.GOOS != "windows" {
+		err := os.WriteFile(leafFile, nil, 0o666)
+		qt.Assert(t, qt.IsNil(err))
 	}
-	if want := map[string]interface{}{"files": []string{"testdata/input.foo"}}; !reflect.DeepEqual(got, want) {
-		t.Errorf("got %v; want %v", got, want)
+
+	v := parse(t, "tool/file.Glob", `{
+		glob: "`+filepath.ToSlash(dir)+`/\\**"
+	}`)
+	got, err := (*cmdGlob).Run(nil, &task.Context{Obj: v})
+	if runtime.GOOS == "windows" {
+		// TODO(mvdan): this should fail; right now "**" happens to behave like "*".
+		qt.Assert(t, qt.IsNil(err))
+		qt.Assert(t, qt.DeepEquals(got, any(map[string]any{"files": []string(nil)})))
+	} else {
+		qt.Assert(t, qt.IsNil(err))
+		qt.Assert(t, qt.DeepEquals(got, any(map[string]any{"files": []string{leafFile}})))
 	}
 }