Partial update

.gitignore

@@ -1 +1,2 @@
 dist/
+.idea/

internal/filesystem/file.go

@@ -1,8 +1,10 @@
 package filesystem
 
 import (
+ "bytes"
  "path/filepath"
 
+ "github.com/hashicorp/hcl/v2"
  "github.com/hashicorp/terraform-ls/internal/source"
  encunicode "golang.org/x/text/encoding/unicode"
 )
@@ -16,8 +18,9 @@ type file struct {
  content []byte
  open bool
 
- ls source.Lines
- errs bool
+ version int
+ ls source.Lines
+ errs bool
 }
 
 func NewFile(fullPath string, content []byte) *file {
@@ -40,6 +43,14 @@ func (f *file) URI() string {
  return URIFromPath(f.fullPath)
 }
 
+func (f *file) Version() int {
+ return f.version
+}
+
+func (f *file) SetVersion(version int) {
+ f.version = version
+}
+
 func (f *file) Lines() source.Lines {
  if f.ls == nil {
  f.ls = source.MakeSourceLines(f.Filename(), f.content)
@@ -52,13 +63,33 @@ func (f *file) Text() []byte {
 }
 
 func (f *file) applyChange(change FileChange) error {
- newBytes := []byte(change.Text())
- f.change(newBytes)
+ // if the range is regarded as nil, we regard it as full content change
+ if rangeIsNil(change.Range()) {
+ f.change([]byte(change.Text()))
+ return nil
+ }
+ b := &bytes.Buffer{}
+ b.Grow(len(f.content) + diffLen(change))
+ b.Write(f.content[:change.Range().Start.Byte])
+ b.WriteString(change.Text())
+ b.Write(f.content[change.Range().End.Byte:])
 
+ f.change(b.Bytes())
  return nil
 }
 
 func (f *file) change(s []byte) {
  f.content = s
  f.ls = nil
 }
+
+// HCL column and line indexes start from 1, therefore if the any index
+// contains 0, we assume it is an undefined range
+func rangeIsNil(r hcl.Range) bool {
+ return r.End.Column == 0 && r.End.Line == 0
+}
+
+func diffLen(change FileChange) int {
+ rangeLen := change.Range().End.Byte - change.Range().Start.Byte
+ return len(change.Text()) - rangeLen
+}

internal/filesystem/file_test.go

@@ -18,16 +18,139 @@ func TestFile_ApplyChange_fullUpdate(t *testing.T) {
  }
 }
 
+func TestFile_ApplyChange_partialUpdate(t *testing.T) {
+ testData := []struct {
+ Name string
+ Content string
+ FileChange *fileChange
+ Expect string
+ }{
+ {
+ Name: "length grow: 4",
+ Content: "hello world",
+ FileChange: &fileChange{
+ text: "terraform",
+ rng: hcl.Range{
+ Start: hcl.Pos{
+ Line: 1,
+ Column: 7,
+ Byte: 6,
+ },
+ End: hcl.Pos{
+ Line: 1,
+ Column: 12,
+ Byte: 11,
+ },
+ },
+ },
+ Expect: "hello terraform",
+ },
+ {
+ Name: "length the same",
+ Content: "hello world",
+ FileChange: &fileChange{
+ text: "earth",
+ rng: hcl.Range{
+ Start: hcl.Pos{
+ Line: 1,
+ Column: 7,
+ Byte: 6,
+ },
+ End: hcl.Pos{
+ Line: 1,
+ Column: 12,
+ Byte: 11,
+ },
+ },
+ },
+ Expect: "hello earth",
+ },
+ {
+ Name: "length grow: -2",
+ Content: "hello world",
+ FileChange: &fileChange{
+ text: "HCL",
+ rng: hcl.Range{
+ Start: hcl.Pos{
+ Line: 1,
+ Column: 7,
+ Byte: 6,
+ },
+ End: hcl.Pos{
+ Line: 1,
+ Column: 12,
+ Byte: 11,
+ },
+ },
+ },
+ Expect: "hello HCL",
+ },
+ {
+ Name: "add utf-18 character",
+ Content: "hello world",
+ FileChange: &fileChange{
+ text: "𐐀𐐀 ",
+ rng: hcl.Range{
+ Start: hcl.Pos{
+ Line: 1,
+ Column: 7,
+ Byte: 6,
+ },
+ End: hcl.Pos{
+ Line: 1,
+ Column: 7,
+ Byte: 6,
+ },
+ },
+ },
+ Expect: "hello 𐐀𐐀 world",
+ },
+ {
+ Name: "modify when containing utf-18 character",
+ Content: "hello 𐐀𐐀 world",
+ FileChange: &fileChange{
+ text: "aa𐐀",
+ rng: hcl.Range{
+ Start: hcl.Pos{
+ Line: 1,
+ Column: 9,
+ Byte: 10,
+ },
+ End: hcl.Pos{
+ Line: 1,
+ Column: 11,
+ Byte: 14,
+ },
+ },
+ },
+ Expect: "hello 𐐀aa𐐀 world",
+ },
+ }
+
+ for _, v := range testData {
+ t.Logf("[DEBUG] Testing %q", v.Name)
+
+ f := NewFile("file:///test.tf", []byte(v.Content))
+ err := f.applyChange(v.FileChange)
+ if err != nil {
+ t.Fatal(err)
+ }
+
+ if string(f.content) != v.Expect {
+ t.Fatalf("expected: %q but actually: %q", v.Expect, string(f.content))
+ }
+ }
+}
+
 type fileChange struct {
  text string
+ rng hcl.Range
 }
 
 func (fc *fileChange) Text() string {
  return fc.text
 }
 
 func (fc *fileChange) Range() hcl.Range {
- return hcl.Range{
- // TODO: Implement partial updates
- }
+ return fc.rng
 }

internal/filesystem/filesystem.go

@@ -39,6 +39,7 @@ func (fs *fsystem) Open(file File) error {
  f = NewFile(file.FullPath(), file.Text())
  }
  f.open = true
+ f.version = file.Version()
  d.files[file.Filename()] = f
  return nil
 }
@@ -54,6 +55,7 @@ func (fs *fsystem) Change(fh VersionedFileHandler, changes FileChanges) error {
  for _, change := range changes {
  f.applyChange(change)
  }
+ f.SetVersion(fh.Version())
  return nil
 }
 

internal/filesystem/filesystem_test.go

@@ -4,15 +4,14 @@ import (
  "testing"
 
  "github.com/google/go-cmp/cmp"
- "github.com/hashicorp/hcl/v2"
  "github.com/hashicorp/terraform-ls/internal/source"
 )
 
 func TestFilesystem_Change_notOpen(t *testing.T) {
  fs := NewFilesystem()
 
  var changes FileChanges
- changes = append(changes, &testChange{})
+ changes = append(changes, &fileChange{})
  h := &testHandler{"file:///doesnotexist"}
 
  err := fs.Change(h, changes)
@@ -41,7 +40,7 @@ func TestFilesystem_Change_closed(t *testing.T) {
  }
 
  var changes FileChanges
- changes = append(changes, &testChange{})
+ changes = append(changes, &fileChange{})
  err = fs.Change(fh, changes)
 
  expectedErr := &FileNotOpenErr{fh}
@@ -105,10 +104,10 @@ func TestFilesystem_Change_multipleChanges(t *testing.T) {
  })
 
  var changes FileChanges
- changes = append(changes, &testChange{text: "ahoy"})
- changes = append(changes, &testChange{text: ""})
- changes = append(changes, &testChange{text: "quick brown fox jumped over\nthe lazy dog"})
- changes = append(changes, &testChange{text: "bye"})
+ changes = append(changes, &fileChange{text: "ahoy"})
+ changes = append(changes, &fileChange{text: ""})
+ changes = append(changes, &fileChange{text: "quick brown fox jumped over\nthe lazy dog"})
+ changes = append(changes, &fileChange{text: "bye"})
 
  err := fs.Change(fh, changes)
  if err != nil {
@@ -196,17 +195,3 @@ func (fh *testHandler) Filename() string {
 func (fh *testHandler) Version() int {
  return 0
 }
-
-type testChange struct {
- text string
-}
-
-func (ch *testChange) Text() string {
- return ch.text
-}
-
-func (ch *testChange) Range() hcl.Range {
- return hcl.Range{
- // TODO: Implement partial updates
- }
-}

internal/filesystem/types.go

@@ -9,6 +9,7 @@ type File interface {
  FileHandler
  Text() []byte
  Lines() source.Lines
+ Version() int
 }
 
 type FilePosition interface {

internal/lsp/file.go

@@ -14,9 +14,10 @@ type File interface {
 }
 
 type file struct {
- fh FileHandler
- ls source.Lines
- text []byte
+ fh FileHandler
+ ls source.Lines
+ text []byte
+ version int
 }
 
 func (f *file) URI() string {
@@ -50,9 +51,14 @@ func (f *file) lines() source.Lines {
  return f.ls
 }
 
+func (f *file) Version() int {
+ return f.version
+}
+
 func FileFromDocumentItem(doc lsp.TextDocumentItem) *file {
  return &file{
- fh: FileHandler(doc.URI),
- text: []byte(doc.Text),
+ fh: FileHandler(doc.URI),
+ text: []byte(doc.Text),
+ version: doc.Version,
  }
 }

internal/lsp/file_change.go

@@ -1,8 +1,6 @@
 package lsp
 
 import (
- "fmt"
-
  "github.com/hashicorp/hcl/v2"
  "github.com/hashicorp/terraform-ls/internal/filesystem"
  "github.com/sourcegraph/go-lsp"
@@ -15,7 +13,15 @@ type fileChange struct {
 
 func FileChange(chEvent lsp.TextDocumentContentChangeEvent, f File) (*fileChange, error) {
  if chEvent.Range != nil {
- return nil, fmt.Errorf("Partial updates are not supported (yet)")
+ rng, err := lspRangeToHCL(*chEvent.Range, f)
+ if err != nil {
+ return nil, err
+ }
+
+ return &fileChange{
+ text: chEvent.Text,
+ rng: *rng,
+ }, nil
  }
 
  return &fileChange{
@@ -61,6 +67,24 @@ func hclRangeToLSP(hclRng hcl.Range) lsp.Range {
  }
 }
 
+func lspRangeToHCL(lspRng lsp.Range, f File) (*hcl.Range, error) {
+ startPos, err := lspPositionToHCL(f.Lines(), lspRng.Start)
+ if err != nil {
+ return nil, err
+ }
+
+ endPos, err := lspPositionToHCL(f.Lines(), lspRng.End)
+ if err != nil {
+ return nil, err
+ }
+
+ return &hcl.Range{
+ Filename: f.Filename(),
+ Start: startPos,
+ End: endPos,
+ }, nil
+}
+
 func (fc *fileChange) Text() string {
  return fc.text
 }