diff --git a/gopls/internal/regtest/completion/completion_test.go b/gopls/internal/regtest/completion/completion_test.go
index d57a4b237b1..afdd494a8b1 100644
--- a/gopls/internal/regtest/completion/completion_test.go
+++ b/gopls/internal/regtest/completion/completion_test.go
@@ -503,3 +503,41 @@ func doit() {
 		}
 	})
 }
+
+func TestUnimportedCompletion_VSCodeIssue1489(t *testing.T) {
+	t.Skip("broken due to golang/vscode-go#1489")
+	testenv.NeedsGo1Point(t, 14)
+
+	const src = `
+-- go.mod --
+module mod.com
+
+go 1.14
+
+-- main.go --
+package main
+
+import "fmt"
+
+func main() {
+	fmt.Println("a")
+	math.Sqr
+}
+`
+	WithOptions(
+		WindowsLineEndings,
+		ProxyFiles(proxy),
+	).Run(t, src, func(t *testing.T, env *Env) {
+		// Trigger unimported completions for the example.com/blah package.
+		env.OpenFile("main.go")
+		env.Await(env.DoneWithOpen())
+		pos := env.RegexpSearch("main.go", "Sqr()")
+		completions := env.Completion("main.go", pos)
+		if len(completions.Items) == 0 {
+			t.Fatalf("no completion items")
+		}
+		env.AcceptCompletion("main.go", pos, completions.Items[0])
+		env.Await(env.DoneWithChange())
+		t.Log(env.Editor.BufferText("main.go"))
+	})
+}
diff --git a/internal/lsp/cache/view_test.go b/internal/lsp/cache/view_test.go
index cb57182353f..802215a5aac 100644
--- a/internal/lsp/cache/view_test.go
+++ b/internal/lsp/cache/view_test.go
@@ -66,7 +66,7 @@ module de
 -- f/g/go.mod --
 module fg
 `
-	dir, err := fake.Tempdir(workspace)
+	dir, err := fake.Tempdir(fake.UnpackTxt(workspace))
 	if err != nil {
 		t.Fatal(err)
 	}
diff --git a/internal/lsp/cache/workspace_test.go b/internal/lsp/cache/workspace_test.go
index fd9cb8d1d3c..85240611645 100644
--- a/internal/lsp/cache/workspace_test.go
+++ b/internal/lsp/cache/workspace_test.go
@@ -269,7 +269,7 @@ replace gopls.test => ../../gopls.test2`, false},
 	for _, test := range tests {
 		t.Run(test.desc, func(t *testing.T) {
 			ctx := context.Background()
-			dir, err := fake.Tempdir(test.initial)
+			dir, err := fake.Tempdir(fake.UnpackTxt(test.initial))
 			if err != nil {
 				t.Fatal(err)
 			}
diff --git a/internal/lsp/fake/editor.go b/internal/lsp/fake/editor.go
index de01f0b38a8..501d32c1806 100644
--- a/internal/lsp/fake/editor.go
+++ b/internal/lsp/fake/editor.go
@@ -55,14 +55,19 @@ type CallCounts struct {
 }
 
 type buffer struct {
-	version int
-	path    string
-	lines   []string
-	dirty   bool
+	windowsLineEndings bool
+	version            int
+	path               string
+	lines              []string
+	dirty              bool
 }
 
 func (b buffer) text() string {
-	return strings.Join(b.lines, "\n")
+	eol := "\n"
+	if b.windowsLineEndings {
+		eol = "\r\n"
+	}
+	return strings.Join(b.lines, eol)
 }
 
 // EditorConfig configures the editor's LSP session. This is similar to
@@ -106,6 +111,9 @@ type EditorConfig struct {
 	// the PID. This can only be set by one test.
 	SendPID bool
 
+	// Whether to edit files with windows line endings.
+	WindowsLineEndings bool
+
 	DirectoryFilters []string
 
 	VerboseOutput bool
@@ -338,11 +346,11 @@ func (e *Editor) onFileChanges(ctx context.Context, evts []FileEvent) {
 					continue // A race with some other operation.
 				}
 				// No need to update if the buffer content hasn't changed.
-				if content == strings.Join(buf.lines, "\n") {
+				if content == buf.text() {
 					continue
 				}
 				// During shutdown, this call will fail. Ignore the error.
-				_ = e.setBufferContentLocked(ctx, evt.Path, false, strings.Split(content, "\n"), nil)
+				_ = e.setBufferContentLocked(ctx, evt.Path, false, lines(content), nil)
 			}
 		}
 		e.Server.DidChangeWatchedFiles(ctx, &protocol.DidChangeWatchedFilesParams{
@@ -383,10 +391,11 @@ func (e *Editor) CreateBuffer(ctx context.Context, path, content string) error {
 
 func (e *Editor) createBuffer(ctx context.Context, path string, dirty bool, content string) error {
 	buf := buffer{
-		version: 1,
-		path:    path,
-		lines:   strings.Split(content, "\n"),
-		dirty:   dirty,
+		windowsLineEndings: e.Config.WindowsLineEndings,
+		version:            1,
+		path:               path,
+		lines:              lines(content),
+		dirty:              dirty,
 	}
 	e.mu.Lock()
 	defer e.mu.Unlock()
@@ -406,6 +415,15 @@ func (e *Editor) createBuffer(ctx context.Context, path string, dirty bool, cont
 	return nil
 }
 
+// lines returns line-ending agnostic line representation of content.
+func lines(content string) []string {
+	lines := strings.Split(content, "\n")
+	for i, l := range lines {
+		lines[i] = strings.TrimSuffix(l, "\r")
+	}
+	return lines
+}
+
 // CloseBuffer removes the current buffer (regardless of whether it is saved).
 func (e *Editor) CloseBuffer(ctx context.Context, path string) error {
 	e.mu.Lock()
@@ -528,6 +546,7 @@ var (
 // regexpRange returns the start and end of the first occurrence of either re
 // or its singular subgroup. It returns ErrNoMatch if the regexp doesn't match.
 func regexpRange(content, re string) (Pos, Pos, error) {
+	content = normalizeEOL(content)
 	var start, end int
 	rec, err := regexp.Compile(re)
 	if err != nil {
@@ -558,6 +577,10 @@ func regexpRange(content, re string) (Pos, Pos, error) {
 	return startPos, endPos, nil
 }
 
+func normalizeEOL(content string) string {
+	return strings.Join(lines(content), "\n")
+}
+
 // RegexpRange returns the first range in the buffer bufName matching re. See
 // RegexpSearch for more information on matching.
 func (e *Editor) RegexpRange(bufName, re string) (Pos, Pos, error) {
@@ -615,7 +638,7 @@ func (e *Editor) EditBuffer(ctx context.Context, path string, edits []Edit) erro
 func (e *Editor) SetBufferContent(ctx context.Context, path, content string) error {
 	e.mu.Lock()
 	defer e.mu.Unlock()
-	lines := strings.Split(content, "\n")
+	lines := lines(content)
 	return e.setBufferContentLocked(ctx, path, true, lines, nil)
 }
 
diff --git a/internal/lsp/fake/editor_test.go b/internal/lsp/fake/editor_test.go
index f1ce7537ae5..3ce5df6e08f 100644
--- a/internal/lsp/fake/editor_test.go
+++ b/internal/lsp/fake/editor_test.go
@@ -48,7 +48,7 @@ func main() {
 `
 
 func TestClientEditing(t *testing.T) {
-	ws, err := NewSandbox(&SandboxConfig{Files: exampleProgram})
+	ws, err := NewSandbox(&SandboxConfig{Files: UnpackTxt(exampleProgram)})
 	if err != nil {
 		t.Fatal(err)
 	}
diff --git a/internal/lsp/fake/proxy.go b/internal/lsp/fake/proxy.go
index dbba27d76f7..9e56efeb17f 100644
--- a/internal/lsp/fake/proxy.go
+++ b/internal/lsp/fake/proxy.go
@@ -12,8 +12,7 @@ import (
 
 // WriteProxy creates a new proxy file tree using the txtar-encoded content,
 // and returns its URL.
-func WriteProxy(tmpdir, txt string) (string, error) {
-	files := unpackTxt(txt)
+func WriteProxy(tmpdir string, files map[string][]byte) (string, error) {
 	type moduleVersion struct {
 		modulePath, version string
 	}
diff --git a/internal/lsp/fake/sandbox.go b/internal/lsp/fake/sandbox.go
index c14f9035ac3..34f1ba180c0 100644
--- a/internal/lsp/fake/sandbox.go
+++ b/internal/lsp/fake/sandbox.go
@@ -38,7 +38,7 @@ type SandboxConfig struct {
 	//
 	// For convenience, the special substring "$SANDBOX_WORKDIR" is replaced with
 	// the sandbox's resolved working directory before writing files.
-	Files string
+	Files map[string][]byte
 	// InGoPath specifies that the working directory should be within the
 	// temporary GOPATH.
 	InGoPath bool
@@ -51,10 +51,9 @@ type SandboxConfig struct {
 	//
 	// This option is incompatible with InGoPath or Files.
 	Workdir string
-
 	// ProxyFiles holds a txtar-encoded archive of files to populate a file-based
 	// Go proxy.
-	ProxyFiles string
+	ProxyFiles map[string][]byte
 	// GOPROXY is the explicit GOPROXY value that should be used for the sandbox.
 	//
 	// This option is incompatible with ProxyFiles.
@@ -141,12 +140,11 @@ func NewSandbox(config *SandboxConfig) (_ *Sandbox, err error) {
 // Tempdir creates a new temp directory with the given txtar-encoded files. It
 // is the responsibility of the caller to call os.RemoveAll on the returned
 // file path when it is no longer needed.
-func Tempdir(txt string) (string, error) {
+func Tempdir(files map[string][]byte) (string, error) {
 	dir, err := ioutil.TempDir("", "gopls-tempdir-")
 	if err != nil {
 		return "", err
 	}
-	files := unpackTxt(txt)
 	for name, data := range files {
 		if err := WriteFileData(name, data, RelativeTo(dir)); err != nil {
 			return "", errors.Errorf("writing to tempdir: %w", err)
@@ -155,7 +153,7 @@ func Tempdir(txt string) (string, error) {
 	return dir, nil
 }
 
-func unpackTxt(txt string) map[string][]byte {
+func UnpackTxt(txt string) map[string][]byte {
 	dataMap := make(map[string][]byte)
 	archive := txtar.Parse([]byte(txt))
 	for _, f := range archive.Files {
@@ -165,13 +163,13 @@ func unpackTxt(txt string) map[string][]byte {
 }
 
 func validateConfig(config SandboxConfig) error {
-	if filepath.IsAbs(config.Workdir) && (config.Files != "" || config.InGoPath) {
+	if filepath.IsAbs(config.Workdir) && (config.Files != nil || config.InGoPath) {
 		return errors.New("absolute Workdir cannot be set in conjunction with Files or InGoPath")
 	}
 	if config.Workdir != "" && config.InGoPath {
 		return errors.New("Workdir cannot be set in conjunction with InGoPath")
 	}
-	if config.GOPROXY != "" && config.ProxyFiles != "" {
+	if config.GOPROXY != "" && config.ProxyFiles != nil {
 		return errors.New("GOPROXY cannot be set in conjunction with ProxyFiles")
 	}
 	return nil
diff --git a/internal/lsp/fake/workdir.go b/internal/lsp/fake/workdir.go
index 5103bdb4e19..aa9ef84df67 100644
--- a/internal/lsp/fake/workdir.go
+++ b/internal/lsp/fake/workdir.go
@@ -50,7 +50,7 @@ func (r RelativeTo) RelPath(fp string) string {
 }
 
 func writeTxtar(txt string, rel RelativeTo) error {
-	files := unpackTxt(txt)
+	files := UnpackTxt(txt)
 	for name, data := range files {
 		if err := WriteFileData(name, data, rel); err != nil {
 			return errors.Errorf("writing to workdir: %w", err)
@@ -96,8 +96,7 @@ func hashFile(data []byte) string {
 	return fmt.Sprintf("%x", sha256.Sum256(data))
 }
 
-func (w *Workdir) writeInitialFiles(txt string) error {
-	files := unpackTxt(txt)
+func (w *Workdir) writeInitialFiles(files map[string][]byte) error {
 	w.files = map[string]string{}
 	for name, data := range files {
 		w.files[name] = hashFile(data)
diff --git a/internal/lsp/fake/workdir_test.go b/internal/lsp/fake/workdir_test.go
index f57ea37e13b..33fbb9fa1d5 100644
--- a/internal/lsp/fake/workdir_test.go
+++ b/internal/lsp/fake/workdir_test.go
@@ -30,7 +30,7 @@ func newWorkdir(t *testing.T) (*Workdir, <-chan []FileEvent, func()) {
 		t.Fatal(err)
 	}
 	wd := NewWorkdir(tmpdir)
-	if err := wd.writeInitialFiles(data); err != nil {
+	if err := wd.writeInitialFiles(UnpackTxt(data)); err != nil {
 		t.Fatal(err)
 	}
 	cleanup := func() {
diff --git a/internal/lsp/lsprpc/lsprpc_test.go b/internal/lsp/lsprpc/lsprpc_test.go
index 5fa6b9715f5..ef2555d9f1c 100644
--- a/internal/lsp/lsprpc/lsprpc_test.go
+++ b/internal/lsp/lsprpc/lsprpc_test.go
@@ -197,7 +197,7 @@ func main() {
 }`
 
 func TestDebugInfoLifecycle(t *testing.T) {
-	sb, err := fake.NewSandbox(&fake.SandboxConfig{Files: exampleProgram})
+	sb, err := fake.NewSandbox(&fake.SandboxConfig{Files: fake.UnpackTxt(exampleProgram)})
 	if err != nil {
 		t.Fatal(err)
 	}
diff --git a/internal/lsp/regtest/runner.go b/internal/lsp/regtest/runner.go
index 87cfa6de63a..5eeacd8634e 100644
--- a/internal/lsp/regtest/runner.go
+++ b/internal/lsp/regtest/runner.go
@@ -109,7 +109,7 @@ func Timeout(d time.Duration) RunOption {
 // ProxyFiles configures a file proxy using the given txtar-encoded string.
 func ProxyFiles(txt string) RunOption {
 	return optionSetter(func(opts *runConfig) {
-		opts.sandbox.ProxyFiles = txt
+		opts.sandbox.ProxyFiles = fake.UnpackTxt(txt)
 	})
 }
 
@@ -177,6 +177,10 @@ func DebugAddress(addr string) RunOption {
 	})
 }
 
+var WindowsLineEndings = optionSetter(func(opts *runConfig) {
+	opts.editor.WindowsLineEndings = true
+})
+
 // SkipLogs skips the buffering of logs during test execution. It is intended
 // for long-running stress tests.
 func SkipLogs() RunOption {
@@ -269,6 +273,12 @@ func (r *Runner) Run(t *testing.T, files string, test TestFunc, opts ...RunOptio
 			if err := os.MkdirAll(rootDir, 0755); err != nil {
 				t.Fatal(err)
 			}
+			files := fake.UnpackTxt(files)
+			if config.editor.WindowsLineEndings {
+				for name, data := range files {
+					files[name] = bytes.ReplaceAll(data, []byte("\n"), []byte("\r\n"))
+				}
+			}
 			config.sandbox.Files = files
 			config.sandbox.RootDir = rootDir
 			sandbox, err := fake.NewSandbox(&config.sandbox)
@@ -385,7 +395,7 @@ func singletonServer(ctx context.Context, t *testing.T, optsHook func(*source.Op
 	return lsprpc.NewStreamServer(cache.New(optsHook), false)
 }
 
-func experimentalWorkspaceModule(_ context.Context, t *testing.T, optsHook func(*source.Options)) jsonrpc2.StreamServer {
+func experimentalWorkspaceModule(_ context.Context, _ *testing.T, optsHook func(*source.Options)) jsonrpc2.StreamServer {
 	options := func(o *source.Options) {
 		optsHook(o)
 		o.ExperimentalWorkspaceModule = true