diff --git a/cue/format/format_test.go b/cue/format/format_test.go
index 7b3d4a74a94..a1c92754b86 100644
--- a/cue/format/format_test.go
+++ b/cue/format/format_test.go
@@ -17,19 +17,22 @@ package format
 // TODO: port more of the tests of go/printer
 
 import (
-	"bytes"
-	"fmt"
+	"io/fs"
 	"os"
+	"path"
 	"path/filepath"
+	"strings"
 	"testing"
-	"time"
+
+	"github.com/go-quicktest/qt"
+	"golang.org/x/tools/txtar"
 
 	"cuelang.org/go/cue/ast"
-	"cuelang.org/go/cue/errors"
 	"cuelang.org/go/cue/parser"
 	"cuelang.org/go/cue/token"
 	"cuelang.org/go/internal"
 	"cuelang.org/go/internal/cuetest"
+	"cuelang.org/go/internal/txtarfs"
 )
 
 var (
@@ -37,184 +40,75 @@ var (
 	Fprint        = defaultConfig.fprint
 )
 
-const (
-	dataDir = "testdata"
-)
-
-type checkMode uint
-
-const (
-	_ checkMode = 1 << iota
-	idempotent
-	simplify
-	sortImps
-)
-
-// format parses src, prints the corresponding AST, verifies the resulting
-// src is syntactically correct, and returns the resulting src or an error
-// if any.
-func format(src []byte, mode checkMode) ([]byte, error) {
-	// parse src
-	opts := []Option{TabIndent(true)}
-	if mode&simplify != 0 {
-		opts = append(opts, Simplify())
-	}
-	if mode&sortImps != 0 {
-		opts = append(opts, sortImportsOption())
-	}
-
-	res, err := Source(src, opts...)
-	if err != nil {
-		return nil, err
-	}
-
-	// make sure formatted output is syntactically correct
-	if _, err := parser.ParseFile("", res, parser.AllErrors); err != nil {
-		return nil, errors.Append(err.(errors.Error),
-			errors.Newf(token.NoPos, "re-parse failed: %s", res))
-	}
-
-	return res, nil
-}
-
-// lineAt returns the line in text starting at offset offs.
-func lineAt(text []byte, offs int) []byte {
-	i := offs
-	for i < len(text) && text[i] != '\n' {
-		i++
-	}
-	return text[offs:i]
-}
-
-// diff compares a and b.
-func diff(aname, bname string, a, b []byte) error {
-	var buf bytes.Buffer // holding long error message
-
-	// compare lengths
-	if len(a) != len(b) {
-		fmt.Fprintf(&buf, "\nlength changed: len(%s) = %d, len(%s) = %d", aname, len(a), bname, len(b))
-	}
-
-	// compare contents
-	line := 1
-	offs := 1
-	for i := 0; i < len(a) && i < len(b); i++ {
-		ch := a[i]
-		if ch != b[i] {
-			fmt.Fprintf(&buf, "\n%s:%d:%d: %s", aname, line, i-offs+1, lineAt(a, offs))
-			fmt.Fprintf(&buf, "\n%s:%d:%d: %s", bname, line, i-offs+1, lineAt(b, offs))
-			fmt.Fprintf(&buf, "\n\n")
-			break
-		}
-		if ch == '\n' {
-			line++
-			offs = i + 1
-		}
-	}
-
-	if buf.Len() > 0 {
-		return errors.New(buf.String())
-	}
-	return nil
-}
-
-func runcheck(t *testing.T, source, golden string, mode checkMode) {
-	src, err := os.ReadFile(source)
-	if err != nil {
-		t.Error(err)
-		return
-	}
-
-	res, err := format(src, mode)
-	if err != nil {
-		b := &bytes.Buffer{}
-		errors.Print(b, err, nil)
-		t.Error(b.String())
-		return
-	}
-
-	// update golden files if necessary
-	if cuetest.UpdateGoldenFiles {
-		if err := os.WriteFile(golden, res, 0644); err != nil {
-			t.Error(err)
+func TestFiles(t *testing.T) {
+	txtarFiles, err := filepath.Glob("testdata/*.txtar")
+	qt.Assert(t, qt.IsNil(err))
+	for _, txtarFile := range txtarFiles {
+		ar, err := txtar.ParseFile(txtarFile)
+		qt.Assert(t, qt.IsNil(err))
+
+		opts := []Option{TabIndent(true)}
+		for _, word := range strings.Fields(string(ar.Comment)) {
+			switch word {
+			case "simplify":
+				opts = append(opts, Simplify())
+			case "sort-imports":
+				opts = append(opts, sortImportsOption())
+			}
 		}
-		return
-	}
 
-	// get golden
-	gld, err := os.ReadFile(golden)
-	if err != nil {
-		t.Error(err)
-		return
-	}
-
-	// formatted source and golden must be the same
-	if err := diff(source, golden, res, gld); err != nil {
-		t.Error(err)
-		return
-	}
-
-	if mode&idempotent != 0 {
-		// formatting golden must be idempotent
-		// (This is very difficult to achieve in general and for now
-		// it is only checked for files explicitly marked as such.)
-		res, err = format(gld, mode)
-		if err != nil {
-			t.Fatal(err)
+		tfs := txtarfs.FS(ar)
+		inputFiles, err := fs.Glob(tfs, "*.input")
+		qt.Assert(t, qt.IsNil(err))
+
+		for _, inputFile := range inputFiles {
+			goldenFile := strings.TrimSuffix(inputFile, ".input") + ".golden"
+			t.Run(path.Join(txtarFile, inputFile), func(t *testing.T) {
+				src, err := fs.ReadFile(tfs, inputFile)
+				qt.Assert(t, qt.IsNil(err))
+
+				res, err := Source(src, opts...)
+				qt.Assert(t, qt.IsNil(err))
+
+				// make sure formatted output is syntactically correct
+				_, err = parser.ParseFile("", res, parser.AllErrors)
+				qt.Assert(t, qt.IsNil(err))
+
+				// update golden files if necessary
+				// TODO(mvdan): deduplicate this code with UpdateGoldenFiles on txtar files?
+				if cuetest.UpdateGoldenFiles {
+					for i := range ar.Files {
+						file := &ar.Files[i]
+						if file.Name == goldenFile {
+							file.Data = res
+							return
+						}
+					}
+					ar.Files = append(ar.Files, txtar.File{
+						Name: goldenFile,
+						Data: res,
+					})
+					return
+				}
+
+				// get golden
+				gld, err := fs.ReadFile(tfs, goldenFile)
+				qt.Assert(t, qt.IsNil(err))
+
+				// formatted source and golden must be the same
+				qt.Assert(t, qt.Equals(string(res), string(gld)))
+
+				// TODO(mvdan): check that all files format in an idempotent way,
+				// i.e. that formatting a golden file results in no changes.
+			})
 		}
-		if err := diff(golden, fmt.Sprintf("format(%s)", golden), gld, res); err != nil {
-			t.Errorf("golden is not idempotent: %s", err)
+		if cuetest.UpdateGoldenFiles {
+			err = os.WriteFile(txtarFile, txtar.Format(ar), 0o666)
+			qt.Assert(t, qt.IsNil(err))
 		}
 	}
 }
 
-func check(t *testing.T, source, golden string, mode checkMode) {
-	// run the test
-	cc := make(chan int)
-	go func() {
-		runcheck(t, source, golden, mode)
-		cc <- 0
-	}()
-
-	// wait with timeout
-	select {
-	case <-time.After(100000 * time.Second): // plenty of a safety margin, even for very slow machines
-		// test running past time out
-		t.Errorf("%s: running too slowly", source)
-	case <-cc:
-		// test finished within allotted time margin
-	}
-}
-
-type entry struct {
-	source, golden string
-	mode           checkMode
-}
-
-// Set CUE_UPDATE=1 to create/update the respective golden files.
-var data = []entry{
-	{"comments.input", "comments.golden", simplify},
-	{"simplify.input", "simplify.golden", simplify},
-	{"expressions.input", "expressions.golden", 0},
-	{"values.input", "values.golden", 0},
-	{"imports.input", "imports.golden", sortImps},
-}
-
-func TestFiles(t *testing.T) {
-	t.Parallel()
-	for _, e := range data {
-		source := filepath.Join(dataDir, e.source)
-		golden := filepath.Join(dataDir, e.golden)
-		mode := e.mode
-		t.Run(e.source, func(t *testing.T) {
-			t.Parallel()
-			check(t, source, golden, mode)
-			// TODO(gri) check that golden is idempotent
-			//check(t, golden, golden, e.mode)
-		})
-	}
-}
-
 // Verify that the printer can be invoked during initialization.
 func init() {
 	const name = "foobar"
@@ -476,7 +370,7 @@ func TestX(t *testing.T) {
 	const src = `
 
 `
-	b, err := format([]byte(src), simplify)
+	b, err := Source([]byte(src), Simplify())
 	if err != nil {
 		t.Error(err)
 	}
diff --git a/cue/format/testdata/comments.golden b/cue/format/testdata/comments.golden
deleted file mode 100644
index 35c33ea9c75..00000000000
--- a/cue/format/testdata/comments.golden
+++ /dev/null
@@ -1,158 +0,0 @@
-// Package line 1 group 1
-// Package line 2 group 1
-
-// Package line 1 - group 2
-// Package line 2 - group 2
-package comments
-
-// Emit line 1 group 1
-
-// Emit line 1 group 2
-// Emit line 2 group 2
-{
-	// Inside Emit
-}
-
-a: 3 // a line comment
-
-b:  4   // line comment that is last in the file.
-cc: 555 // align comments
-
-// don't simplify
-a: {
-	b: 2
-}
-
-// simplify
-a: {
-	b: c: d: 1
-}
-
-// unchanged
-a: b: [1]
-
-// don't simplify
-a: b: c: 2
-
-// rewrite okay
-a: b: c: d: 2
-
-m: {}
-m: {
-	// empty with comment
-}
-
-// Issue #478
-struct1: {
-	// This is a comment
-
-	// This is a comment
-
-	// Another comment
-
-	something: {}
-	// extra comment
-}
-
-struct2: {
-	// This is a comment
-
-	// This is a comment
-
-	// Another comment
-	something: {}
-
-	// extra comment
-}
-
-list1: [
-	// Comment1
-
-	// Comment2
-
-	// Another comment
-	{},
-
-	// Comment 3
-]
-
-list2: [
-	// foo
-]
-
-list3: [
-	// foo
-
-	// bar
-]
-
-list4: [
-	1,                    // number
-	a.b,                  // selector
-	(a),                  // paren
-	+1,                   // unary
-	a[0],                 // index
-	a[2:3],               // slice
-	strings.Sort([1, 2]), // call
-
-	a.b,
-	// under selector
-
-	a.b,
-	// multiple
-	// under
-
-	// selector
-]
-
-funcArg1: foo(
-		// Comment1
-
-	// Comment2
-	3,
-
-	// Comment3
-	)
-
-funcArg2: foo(
-		// Comment1
-
-	// Comment2
-
-	3,
-	// Comment3
-	)
-
-funcArg3: foo(
-		2,
-
-	// Comment1
-
-	// Comment2
-	3,
-
-	// Comment3
-	)
-
-//	comment including		some tabs
-
-// issue #2567
-foo: [
-	bar["baz"], //some comment
-]
-
-[
-	if true {}, // inline comment
-]
-
-{
-
-	foo: {
-		// some
-		... // comment
-	}
-	// comments
-	... // surrounding
-
-	// an ellipsis
-}
diff --git a/cue/format/testdata/comments.input b/cue/format/testdata/comments.txtar
similarity index 50%
rename from cue/format/testdata/comments.input
rename to cue/format/testdata/comments.txtar
index 85257ac7497..87c2bd4bbb6 100644
--- a/cue/format/testdata/comments.input
+++ b/cue/format/testdata/comments.txtar
@@ -1,3 +1,6 @@
+simplify
+
+-- comments.input --
 // Package line 1 group 1
 // Package line 2 group 1
 
@@ -166,4 +169,163 @@ foo: [
         // some
         [string]: _ // comment
     }
-}
\ No newline at end of file
+}
+-- comments.golden --
+// Package line 1 group 1
+// Package line 2 group 1
+
+// Package line 1 - group 2
+// Package line 2 - group 2
+package comments
+
+// Emit line 1 group 1
+
+// Emit line 1 group 2
+// Emit line 2 group 2
+{
+	// Inside Emit
+}
+
+a: 3 // a line comment
+
+b:  4   // line comment that is last in the file.
+cc: 555 // align comments
+
+// don't simplify
+a: {
+	b: 2
+}
+
+// simplify
+a: {
+	b: c: d: 1
+}
+
+// unchanged
+a: b: [1]
+
+// don't simplify
+a: b: c: 2
+
+// rewrite okay
+a: b: c: d: 2
+
+m: {}
+m: {
+	// empty with comment
+}
+
+// Issue #478
+struct1: {
+	// This is a comment
+
+	// This is a comment
+
+	// Another comment
+
+	something: {}
+	// extra comment
+}
+
+struct2: {
+	// This is a comment
+
+	// This is a comment
+
+	// Another comment
+	something: {}
+
+	// extra comment
+}
+
+list1: [
+	// Comment1
+
+	// Comment2
+
+	// Another comment
+	{},
+
+	// Comment 3
+]
+
+list2: [
+	// foo
+]
+
+list3: [
+	// foo
+
+	// bar
+]
+
+list4: [
+	1,                    // number
+	a.b,                  // selector
+	(a),                  // paren
+	+1,                   // unary
+	a[0],                 // index
+	a[2:3],               // slice
+	strings.Sort([1, 2]), // call
+
+	a.b,
+	// under selector
+
+	a.b,
+	// multiple
+	// under
+
+	// selector
+]
+
+funcArg1: foo(
+		// Comment1
+
+	// Comment2
+	3,
+
+	// Comment3
+	)
+
+funcArg2: foo(
+		// Comment1
+
+	// Comment2
+
+	3,
+	// Comment3
+	)
+
+funcArg3: foo(
+		2,
+
+	// Comment1
+
+	// Comment2
+	3,
+
+	// Comment3
+	)
+
+//	comment including		some tabs
+
+// issue #2567
+foo: [
+	bar["baz"], //some comment
+]
+
+[
+	if true {}, // inline comment
+]
+
+{
+
+	foo: {
+		// some
+		... // comment
+	}
+	// comments
+	... // surrounding
+
+	// an ellipsis
+}
diff --git a/cue/format/testdata/expressions.golden b/cue/format/testdata/expressions.golden
deleted file mode 100644
index aff4893a42c..00000000000
--- a/cue/format/testdata/expressions.golden
+++ /dev/null
@@ -1,281 +0,0 @@
-package expressions
-
-import "list"
-
-{
-	a:   1  // comment
-	aaa: 22 // comment
-
-	"": 3
-
-	b: 3
-
-	c: b: a:       4
-	c?: bb?: aaa?: 5
-	c: b: [Name=string]: a: int
-	let alias = 3.14
-	"g\("en")"?: 4
-
-	let alias2 = foo // with comment
-	let aaalias = foo
-	b: bar
-
-	bottom: _|_
-
-	a:
-		b:
-			c: 2
-
-	req!: int
-
-	a: bbbb: c: 3
-	a: b: 3
-	a: bb: cc: 3
-
-	empty: {}
-	emptyNewLine: {}
-	someObject: {
-		a:   8
-		aa:  9
-		aaa: 10
-	}
-
-	#someDefinition: {
-		embedding
-
-		field: 2
-	}
-
-	#openDef: {
-		a: int
-		...
-	}
-
-	attrs: {
-		a:    8 @go(A) // comment
-		aa:   8 @go(A) // comment
-		bb:   9
-		bbb:  10  @go(Bbb) @xml(,attr)  // comment
-		bbbb: 100 @go(Bbbb) @xml(,attr) // comment
-	}
-
-	foo: {
-		bar: string @go(-)
-	}
-
-	e:  1 + 2*3
-	e:  1 * 2 * 3 // error
-	e:  >=2 & <=3
-	e:  >2 & <=(3 + 4)
-	ex: >2 & <=(3 + 4*5)
-	e:  >2 & <=3 & <=4
-	e:  1 + 2 + 3 // error
-
-	e: s[1+2]
-	e: s[1:2]
-	e: s[1+2 : 2+4]
-	e: s[2]
-	e: s[2*3]
-	e: s[1+2*3]
-
-	e: a |
-		b |
-		c
-
-	e:
-		a |
-		b | c |
-		d
-
-	e: f(3 + 4 + 5)
-	e: f(3 * 4 * 5)
-	e: f(3 + 4*5)
-
-	e: f(3 + 4 div 5)
-
-	e: 3 < 4 && 5 > 4
-	e: a || b && c || d
-
-	e: a + +b*3
-	e: -a - -b
-
-	e: b + c
-	e: b*c + d
-	e: a*b + c
-	e: a - b - c
-	e: a - (b - c)
-	e: a - b*c
-	e: a - (b * c)
-	e: a * b / c
-	e: a div b + 5
-	e: a / b
-	e: x[a | b]
-	e: x[a/b]
-	e: a & b
-	e: a + +b
-	e: a - -b
-	e: a div -b
-	e: x[a*-b]
-	e: x[a + +b]
-	e: len(longVariableName) * 2
-
-	e: "\(a)"
-	e: 'aa \(aaa) aa'
-	e: "aa \(aaa)"
-
-	e: []
-	e: []
-	e: [1, 2,
-	]
-	e: [1, 2]
-	e: [1, 2, 3, 4,
-		5, 6, 7, 8]
-	e: [1, 2, 3, 4,
-		5, 6, 7, 8, // maybe force additional comma
-	]
-	e: [...]
-	e: [
-		...]
-	e: [...,
-	]
-	e: [1, 2, ...]
-	e: [1, 2,
-		...]
-	e: [...int]
-	e: [...int]
-	e: [...int | float]
-	e: [for x in someObject if x > 9 {
-		x
-	}]
-	e: [for x in someObject if x > 9 {x}]
-	e: [
-		for x in someObject
-		if x > 9 {x}]
-	e: [
-		for x in someObject
-		if x > 9 {x}]
-
-	e: [
-		if x > 1 {},
-		if x > 1 {},
-		for x in src {},
-	]
-
-	for k, v in someObject {
-		"\(k)": v
-	}
-	for k, v in someObject {
-		"\(k)": v
-	}
-
-	e: {
-		for k, v in someObject
-		if k > "a" {
-			"\(k)": v
-		}
-	}
-
-	e: {for k, v in someObject if k > "a" {"\(k)": v}}
-	e: {for k, v in someObject if k > "a" {
-		"\(k)": v
-	}}
-
-	e: {
-		for k, v in someObject
-		let x = v
-		if k > "a" {
-			"\(k)": x
-		}}
-
-	if a |
-		b {
-		c: d
-	}
-
-	e: [{
-		a: 1, b: 2
-	}]
-
-	e: [{
-		a: 1, b: 2
-	},
-	]
-
-	e: [{
-		a: 1, b: 2
-	}, {
-		c: 1, d: 2
-	}]
-
-	e: [{
-		a: 1, b: 2
-	},
-		3,
-		4,
-	]
-
-	e: e.f(1, 2)
-
-	e: (3 + 4)
-
-	// field before list
-	f: 3
-	a: [1, 2, // add comma
-	]
-
-	foo: bar
-
-	a: "foo-bar": 3
-	b: a."foo-bar"
-	c: a."foo-bar".b
-	d: a.
-		"foo-bar"
-	e: a.
-		"foo-bar".
-		b
-	f: 2
-
-	"contains		tabs": 123
-	@jsonschema(foo="contains		tabs")
-
-	j: cueckoo: _ | [
-		1,
-
-		2,
-	]
-	k: cueckoo: *[
-		1,
-
-		2,
-	]
-	l: cueckoo: list.Concat([
-		1,
-
-		2,
-	])
-
-	m: [1, 2, 3]
-	m: [1, 2, 3]
-	m: [1, 2, 3]
-	m: [1, 2, 3]
-	m: [1, 2, 3]
-	m: [1, 2, 3]
-	m: [1, 2, 3]
-	m: [1, 2, 3]
-	m: [1, 2, 3]
-	m: [if true {1}, 2, 3]
-	n: [1]
-	o: [{}]
-	o: [{}]
-	o: [{}]
-	o: [{}]
-
-	p: 1
-	p: p & {p: 2}
-	q: 1
-	q: q | {q: 2}
-	r: 1
-	r: b & [1, 2, {a: 4}]
-	s: [string]: [string]: a
-	s: [string]: {s: string}
-}
diff --git a/cue/format/testdata/expressions.input b/cue/format/testdata/expressions.txtar
similarity index 55%
rename from cue/format/testdata/expressions.input
rename to cue/format/testdata/expressions.txtar
index c63a0bcc6e2..fd41f684c07 100644
--- a/cue/format/testdata/expressions.input
+++ b/cue/format/testdata/expressions.txtar
@@ -1,3 +1,5 @@
+
+-- expressions.input --
 package expressions
 
 import "list"
@@ -281,3 +283,285 @@ import "list"
     s: [string]: [string]: a
     s: [string]: {s: string}
 }
+-- expressions.golden --
+package expressions
+
+import "list"
+
+{
+	a:   1  // comment
+	aaa: 22 // comment
+
+	"": 3
+
+	b: 3
+
+	c: b: a:       4
+	c?: bb?: aaa?: 5
+	c: b: [Name=string]: a: int
+	let alias = 3.14
+	"g\("en")"?: 4
+
+	let alias2 = foo // with comment
+	let aaalias = foo
+	b: bar
+
+	bottom: _|_
+
+	a:
+		b:
+			c: 2
+
+	req!: int
+
+	a: bbbb: c: 3
+	a: b: 3
+	a: bb: cc: 3
+
+	empty: {}
+	emptyNewLine: {}
+	someObject: {
+		a:   8
+		aa:  9
+		aaa: 10
+	}
+
+	#someDefinition: {
+		embedding
+
+		field: 2
+	}
+
+	#openDef: {
+		a: int
+		...
+	}
+
+	attrs: {
+		a:    8 @go(A) // comment
+		aa:   8 @go(A) // comment
+		bb:   9
+		bbb:  10  @go(Bbb) @xml(,attr)  // comment
+		bbbb: 100 @go(Bbbb) @xml(,attr) // comment
+	}
+
+	foo: {
+		bar: string @go(-)
+	}
+
+	e:  1 + 2*3
+	e:  1 * 2 * 3 // error
+	e:  >=2 & <=3
+	e:  >2 & <=(3 + 4)
+	ex: >2 & <=(3 + 4*5)
+	e:  >2 & <=3 & <=4
+	e:  1 + 2 + 3 // error
+
+	e: s[1+2]
+	e: s[1:2]
+	e: s[1+2 : 2+4]
+	e: s[2]
+	e: s[2*3]
+	e: s[1+2*3]
+
+	e: a |
+		b |
+		c
+
+	e:
+		a |
+		b | c |
+		d
+
+	e: f(3 + 4 + 5)
+	e: f(3 * 4 * 5)
+	e: f(3 + 4*5)
+
+	e: f(3 + 4 div 5)
+
+	e: 3 < 4 && 5 > 4
+	e: a || b && c || d
+
+	e: a + +b*3
+	e: -a - -b
+
+	e: b + c
+	e: b*c + d
+	e: a*b + c
+	e: a - b - c
+	e: a - (b - c)
+	e: a - b*c
+	e: a - (b * c)
+	e: a * b / c
+	e: a div b + 5
+	e: a / b
+	e: x[a | b]
+	e: x[a/b]
+	e: a & b
+	e: a + +b
+	e: a - -b
+	e: a div -b
+	e: x[a*-b]
+	e: x[a + +b]
+	e: len(longVariableName) * 2
+
+	e: "\(a)"
+	e: 'aa \(aaa) aa'
+	e: "aa \(aaa)"
+
+	e: []
+	e: []
+	e: [1, 2,
+	]
+	e: [1, 2]
+	e: [1, 2, 3, 4,
+		5, 6, 7, 8]
+	e: [1, 2, 3, 4,
+		5, 6, 7, 8, // maybe force additional comma
+	]
+	e: [...]
+	e: [
+		...]
+	e: [...,
+	]
+	e: [1, 2, ...]
+	e: [1, 2,
+		...]
+	e: [...int]
+	e: [...int]
+	e: [...int | float]
+	e: [for x in someObject if x > 9 {
+		x
+	}]
+	e: [for x in someObject if x > 9 {x}]
+	e: [
+		for x in someObject
+		if x > 9 {x}]
+	e: [
+		for x in someObject
+		if x > 9 {x}]
+
+	e: [
+		if x > 1 {},
+		if x > 1 {},
+		for x in src {},
+	]
+
+	for k, v in someObject {
+		"\(k)": v
+	}
+	for k, v in someObject {
+		"\(k)": v
+	}
+
+	e: {
+		for k, v in someObject
+		if k > "a" {
+			"\(k)": v
+		}
+	}
+
+	e: {for k, v in someObject if k > "a" {"\(k)": v}}
+	e: {for k, v in someObject if k > "a" {
+		"\(k)": v
+	}}
+
+	e: {
+		for k, v in someObject
+		let x = v
+		if k > "a" {
+			"\(k)": x
+		}}
+
+	if a |
+		b {
+		c: d
+	}
+
+	e: [{
+		a: 1, b: 2
+	}]
+
+	e: [{
+		a: 1, b: 2
+	},
+	]
+
+	e: [{
+		a: 1, b: 2
+	}, {
+		c: 1, d: 2
+	}]
+
+	e: [{
+		a: 1, b: 2
+	},
+		3,
+		4,
+	]
+
+	e: e.f(1, 2)
+
+	e: (3 + 4)
+
+	// field before list
+	f: 3
+	a: [1, 2, // add comma
+	]
+
+	foo: bar
+
+	a: "foo-bar": 3
+	b: a."foo-bar"
+	c: a."foo-bar".b
+	d: a.
+		"foo-bar"
+	e: a.
+		"foo-bar".
+		b
+	f: 2
+
+	"contains		tabs": 123
+	@jsonschema(foo="contains		tabs")
+
+	j: cueckoo: _ | [
+		1,
+
+		2,
+	]
+	k: cueckoo: *[
+		1,
+
+		2,
+	]
+	l: cueckoo: list.Concat([
+		1,
+
+		2,
+	])
+
+	m: [1, 2, 3]
+	m: [1, 2, 3]
+	m: [1, 2, 3]
+	m: [1, 2, 3]
+	m: [1, 2, 3]
+	m: [1, 2, 3]
+	m: [1, 2, 3]
+	m: [1, 2, 3]
+	m: [1, 2, 3]
+	m: [if true {1}, 2, 3]
+	n: [1]
+	o: [{}]
+	o: [{}]
+	o: [{}]
+	o: [{}]
+
+	p: 1
+	p: p & {p: 2}
+	q: 1
+	q: q | {q: 2}
+	r: 1
+	r: b & [1, 2, {a: 4}]
+	s: [string]: [string]: a
+	s: [string]: {s: string}
+}
diff --git a/cue/format/testdata/imports.golden b/cue/format/testdata/imports.golden
deleted file mode 100644
index 5d670859cda..00000000000
--- a/cue/format/testdata/imports.golden
+++ /dev/null
@@ -1,26 +0,0 @@
-package foo
-
-import (
-	"cuelang.org/go/foo"
-	"cuelang.org/go/bar"
-	"time"
-)
-
-import (
-	time1 "time"
-
-	// comment f2
-	f2 "cuelang.org/go/foo"
-	f1 "cuelang.org/go/foo"
-)
-
-import (
-	time2 "time"
-
-	same "cuelang.org/go/foo"  // comment 1
-	same2 "cuelang.org/go/foo" // comment 2
-)
-
-a: time.time
-b: foo.foo
-c: bar.Bar
diff --git a/cue/format/testdata/imports.input b/cue/format/testdata/imports.input
deleted file mode 100644
index a6177961103..00000000000
--- a/cue/format/testdata/imports.input
+++ /dev/null
@@ -1,27 +0,0 @@
-package foo
-
-import (
-    "cuelang.org/go/foo"
-    "cuelang.org/go/bar"
-    "time"
-)
-
-import (
-    time1 "time"
-
-    // comment f2
-    f2 "cuelang.org/go/foo"
-    f1 "cuelang.org/go/foo"
-)
-
-import (
-    time2 "time"
-
-    same "cuelang.org/go/foo" // comment 1
-    same2 "cuelang.org/go/foo" // comment 2
-)
-
-
-a: time.time
-b: foo.foo
-c: bar.Bar
\ No newline at end of file
diff --git a/cue/format/testdata/imports.txtar b/cue/format/testdata/imports.txtar
new file mode 100644
index 00000000000..e26dd148b08
--- /dev/null
+++ b/cue/format/testdata/imports.txtar
@@ -0,0 +1,57 @@
+sort-imports
+
+-- imports.input --
+package foo
+
+import (
+    "cuelang.org/go/foo"
+    "cuelang.org/go/bar"
+    "time"
+)
+
+import (
+    time1 "time"
+
+    // comment f2
+    f2 "cuelang.org/go/foo"
+    f1 "cuelang.org/go/foo"
+)
+
+import (
+    time2 "time"
+
+    same "cuelang.org/go/foo" // comment 1
+    same2 "cuelang.org/go/foo" // comment 2
+)
+
+
+a: time.time
+b: foo.foo
+c: bar.Bar
+-- imports.golden --
+package foo
+
+import (
+	"cuelang.org/go/foo"
+	"cuelang.org/go/bar"
+	"time"
+)
+
+import (
+	time1 "time"
+
+	// comment f2
+	f2 "cuelang.org/go/foo"
+	f1 "cuelang.org/go/foo"
+)
+
+import (
+	time2 "time"
+
+	same "cuelang.org/go/foo"  // comment 1
+	same2 "cuelang.org/go/foo" // comment 2
+)
+
+a: time.time
+b: foo.foo
+c: bar.Bar
diff --git a/cue/format/testdata/simplify.golden b/cue/format/testdata/simplify.golden
deleted file mode 100644
index c49c832b184..00000000000
--- a/cue/format/testdata/simplify.golden
+++ /dev/null
@@ -1,84 +0,0 @@
-import "time"
-
-foo: bar: "str"
-
-a: B: 42
-
-"a.b": "foo-": cc_dd: x
-
-@attr(3)
-
-a: b: c: 3
-
-// references to bar are all shadowed and this can be safely turned into
-// an identifier.
-bar: "str"
-
-// These references would be directly referred to if turned into an identifier.
-// The quotes should therefore not be removed.
-"baz1": 3
-"baz2": 3
-"baz3": 3 // TODO: could be simplified.
-
-// These string labels may be turned into an identifier.
-qux:  4
-quux: 5
-
-// TODO(legacy): Don't simplify "hidden" fields for now.
-"_foo": 3
-
-// Issue #294
-"\("x")": "x"
-
-(x):  "foo"
-(x)?: "foo"
-(x)!: "foo"
-
-a: {
-	foo: 2
-	...
-}
-
-"#A": dontSimplify
-
-x: {
-	@tag0(foo)
-	r1: baz1
-	bar: r2: bar
-	r3:     bar
-	E=quux: 3
-
-	@tag1(bar)
-	r4:           quux
-	[baz2="str"]: 4
-	r5:           baz2
-	[baz3="bar"]: name: baz3
-	Time: time.Time
-}
-
-y: {
-	a: {
-		bar: "a-value"
-		[!="bar"]: {}
-	}
-	b: {
-		x: {
-			bar: "bar"
-			baz: "baz"
-			[!={
-				"a": "baz"
-			}.a & !="bar"]: {}
-		}
-		y: {
-			bar: "a-value"
-			({
-				"a": "bar"
-			}.a): {}
-		}
-	}
-}
-
-{
-	foo: {}
-	bar: "foo": foo // removing the quotes would cause a cyclic reference
-}
diff --git a/cue/format/testdata/simplify.input b/cue/format/testdata/simplify.txtar
similarity index 53%
rename from cue/format/testdata/simplify.input
rename to cue/format/testdata/simplify.txtar
index 479e5938079..c7f553b5b57 100644
--- a/cue/format/testdata/simplify.input
+++ b/cue/format/testdata/simplify.txtar
@@ -1,3 +1,6 @@
+simplify
+
+-- simplify.input --
 import "time"
 
 "foo": "bar": "str"
@@ -86,3 +89,88 @@ y: {
     foo: {}
     bar: "foo": foo // removing the quotes would cause a cyclic reference
 }
+-- simplify.golden --
+import "time"
+
+foo: bar: "str"
+
+a: B: 42
+
+"a.b": "foo-": cc_dd: x
+
+@attr(3)
+
+a: b: c: 3
+
+// references to bar are all shadowed and this can be safely turned into
+// an identifier.
+bar: "str"
+
+// These references would be directly referred to if turned into an identifier.
+// The quotes should therefore not be removed.
+"baz1": 3
+"baz2": 3
+"baz3": 3 // TODO: could be simplified.
+
+// These string labels may be turned into an identifier.
+qux:  4
+quux: 5
+
+// TODO(legacy): Don't simplify "hidden" fields for now.
+"_foo": 3
+
+// Issue #294
+"\("x")": "x"
+
+(x):  "foo"
+(x)?: "foo"
+(x)!: "foo"
+
+a: {
+	foo: 2
+	...
+}
+
+"#A": dontSimplify
+
+x: {
+	@tag0(foo)
+	r1: baz1
+	bar: r2: bar
+	r3:     bar
+	E=quux: 3
+
+	@tag1(bar)
+	r4:           quux
+	[baz2="str"]: 4
+	r5:           baz2
+	[baz3="bar"]: name: baz3
+	Time: time.Time
+}
+
+y: {
+	a: {
+		bar: "a-value"
+		[!="bar"]: {}
+	}
+	b: {
+		x: {
+			bar: "bar"
+			baz: "baz"
+			[!={
+				"a": "baz"
+			}.a & !="bar"]: {}
+		}
+		y: {
+			bar: "a-value"
+			({
+				"a": "bar"
+			}.a): {}
+		}
+	}
+}
+
+{
+	foo: {}
+	bar: "foo": foo // removing the quotes would cause a cyclic reference
+}
diff --git a/cue/format/testdata/values.golden b/cue/format/testdata/values.golden
deleted file mode 100644
index c8968aa110e..00000000000
--- a/cue/format/testdata/values.golden
+++ /dev/null
@@ -1,14 +0,0 @@
-a: 0e+1
-a: 0e1
-a: 0e+1
-a: 0e1
-a: 0.3e+1
-a: 0.3e+1
-a: 0.3
-a: 3.0
-a: 3.0T
-a: 3.0e100
-
-s: """
-	x\"\"\"
-	"""
diff --git a/cue/format/testdata/values.input b/cue/format/testdata/values.input
deleted file mode 100644
index b657973e674..00000000000
--- a/cue/format/testdata/values.input
+++ /dev/null
@@ -1,15 +0,0 @@
-a: 0e+1
-a: 0e1
-a: 0E+1
-a: 0E1
-a: .3e+1
-a: .3E+1
-a: .3
-a: 3.
-a: 3.T
-a: 3.e100
-
-
-s: """
-    x\"\"\"
-    """
diff --git a/cue/format/testdata/values.txtar b/cue/format/testdata/values.txtar
new file mode 100644
index 00000000000..becaa39a718
--- /dev/null
+++ b/cue/format/testdata/values.txtar
@@ -0,0 +1,32 @@
+
+-- values.input --
+a: 0e+1
+a: 0e1
+a: 0E+1
+a: 0E1
+a: .3e+1
+a: .3E+1
+a: .3
+a: 3.
+a: 3.T
+a: 3.e100
+
+
+s: """
+    x\"\"\"
+    """
+-- values.golden --
+a: 0e+1
+a: 0e1
+a: 0e+1
+a: 0e1
+a: 0.3e+1
+a: 0.3e+1
+a: 0.3
+a: 3.0
+a: 3.0T
+a: 3.0e100
+
+s: """
+	x\"\"\"
+	"""