formatting: Return diff hunks instead of whole file content

go.mod

@@ -11,6 +11,7 @@ require (
  github.com/hashicorp/hcl/v2 v2.3.0
  github.com/hashicorp/terraform-json v0.4.0
  github.com/mitchellh/cli v1.0.0
+ github.com/pmezard/go-difflib v1.0.0
  github.com/sourcegraph/go-lsp v0.0.0-20200117082640-b19bb38222e2
  github.com/zclconf/go-cty v1.2.1
  golang.org/x/sync v0.0.0-20190911185100-cd5d95a43a6e

internal/hcl/diff.go

@@ -0,0 +1,120 @@
+package hcl
+
+import (
+ "github.com/hashicorp/hcl/v2"
+ "github.com/hashicorp/terraform-ls/internal/filesystem"
+ "github.com/hashicorp/terraform-ls/internal/source"
+ "github.com/pmezard/go-difflib/difflib"
+)
+
+type fileChange struct {
+ newText string
+ rng hcl.Range
+ opCode difflib.OpCode
+}
+
+func (ch *fileChange) Text() string {
+ return ch.newText
+}
+
+func (ch *fileChange) Range() hcl.Range {
+ return ch.rng
+}
+
+const (
+ OpReplace = 'r'
+ OpDelete = 'd'
+ OpInsert = 'i'
+ OpEqual = 'e'
+)
+
+// Diff calculates difference between File's content
+// and after byte sequence and returns it as filesystem.FileChanges
+func Diff(f filesystem.File, after []byte) filesystem.FileChanges {
+ return diffLines(f.Filename(),
+ source.MakeSourceLines(f.Filename(), f.Text()),
+ source.MakeSourceLines(f.Filename(), after))
+}
+
+// diffLines calculates difference between two source.Lines
+// and returns them as filesystem.FileChanges
+func diffLines(filename string, beforeLines, afterLines source.Lines) filesystem.FileChanges {
+ context := 3
+
+ m := difflib.NewMatcher(
+ source.StringLines(beforeLines),
+ source.StringLines(afterLines))
+
+ changes := make(filesystem.FileChanges, 0)
+
+ for _, group := range m.GetGroupedOpCodes(context) {
+ for _, c := range group {
+ beforeStart, beforeEnd := c.I1, c.I2
+ afterStart, afterEnd := c.J1, c.J2
+
+ if c.Tag == OpEqual {
+ continue
+ }
+
+ if c.Tag == OpReplace {
+ var rng hcl.Range
+ var newBytes []byte
+
+ for i, line := range beforeLines[beforeStart:beforeEnd] {
+ if i == 0 {
+ rng = line.Range()
+ continue
+ }
+ rng.End = line.Range().End
+ }
+
+ for _, line := range afterLines[afterStart:afterEnd] {
+ newBytes = append(newBytes, line.Bytes()...)
+ }
+
+ changes = append(changes, &fileChange{
+ newText: string(newBytes),
+ rng: rng,
+ })
+ continue
+ }
+
+ if c.Tag == OpDelete {
+ var deleteRng hcl.Range
+ for i, line := range beforeLines[beforeStart:beforeEnd] {
+ if i == 0 {
+ deleteRng = line.Range()
+ continue
+ }
+ deleteRng.End = line.Range().End
+ }
+ changes = append(changes, &fileChange{
+ newText: "",
+ rng: deleteRng,
+ opCode: c,
+ })
+ continue
+ }
+
+ if c.Tag == OpInsert {
+ var insertRng hcl.Range
+ insertRng.Start = beforeLines[beforeStart-1].Range().End
+ insertRng.End = beforeLines[beforeStart-1].Range().End
+ var newBytes []byte
+
+ for _, line := range afterLines[afterStart:afterEnd] {
+ newBytes = append(newBytes, line.Bytes()...)
+ }
+
+ changes = append(changes, &fileChange{
+ newText: string(newBytes),
+ rng: insertRng,
+ })
+ continue
+ }
+
+ }
+ }
+
+ return changes
+}

internal/hcl/diff_test.go

@@ -0,0 +1,201 @@
+package hcl
+
+import (
+ "fmt"
+ "testing"
+
+ "github.com/google/go-cmp/cmp"
+ "github.com/google/go-cmp/cmp/cmpopts"
+ "github.com/hashicorp/hcl/v2"
+ "github.com/hashicorp/terraform-ls/internal/filesystem"
+ "github.com/hashicorp/terraform-ls/internal/source"
+ "github.com/pmezard/go-difflib/difflib"
+)
+
+func TestDiff(t *testing.T) {
+ testCases := []struct {
+ name string
+ beforeCfg, afterCfg string
+ expectedChanges filesystem.FileChanges
+ }{
+ {
+ "no-op",
+ `aaa
+bbb
+ccc`,
+ `aaa
+bbb
+ccc`,
+ filesystem.FileChanges{},
+ },
+ {
+ "two separate lines replaced",
+ `resource "aws_vpc" "name" {
+ cidr_block = "sdf"
+ tags = {
+ "key" = "value"
+ sdfasd = 1
+ s = 3
+ }
+}`,
+ `resource "aws_vpc" "name" {
+ cidr_block = "sdf"
+ tags = {
+ "key" = "value"
+ sdfasd = 1
+ s = 3
+ }
+}`,
+ filesystem.FileChanges{
+ &fileChange{
+ newText: ` "key" = "value"
+`,
+ rng: hcl.Range{
+ Filename: "test.tf",
+ Start: hcl.Pos{Line: 4, Column: 1, Byte: 60},
+ End: hcl.Pos{Line: 5, Column: 1, Byte: 80},
+ },
+ },
+ &fileChange{
+ newText: ` s = 3
+`,
+ rng: hcl.Range{
+ Filename: "test.tf",
+ Start: hcl.Pos{Line: 6, Column: 1, Byte: 95},
+ End: hcl.Pos{Line: 7, Column: 1, Byte: 105},
+ },
+ },
+ },
+ },
+ {
+ "whitespace shrinking",
+ `resource "aws_vpc" "name" {
+ cidr_block = "sdf"
+ tags = {
+ "key" = "value"
+ sdfasd = 1
+ s = 3
+
+
+ }
+}`,
+ `resource "aws_vpc" "name" {
+ cidr_block = "sdf"
+ tags = {
+ "key" = "value"
+ sdfasd = 1
+ s = 3
+ }
+}`,
+ filesystem.FileChanges{
+ &fileChange{
+ newText: "",
+ rng: hcl.Range{
+ Filename: "test.tf",
+ Start: hcl.Pos{Line: 7, Column: 1, Byte: 111},
+ End: hcl.Pos{Line: 9, Column: 1, Byte: 113},
+ },
+ },
+ },
+ },
+ {
+ "trailing whitespace removal",
+ `resource "aws_vpc" "name" {
+ 
+}`,
+ `resource "aws_vpc" "name" {
+
+}`,
+ filesystem.FileChanges{
+ &fileChange{
+ newText: "\n",
+ rng: hcl.Range{
+ Filename: "test.tf",
+ Start: hcl.Pos{Line: 2, Column: 1, Byte: 28},
+ End: hcl.Pos{Line: 3, Column: 1, Byte: 31},
+ },
+ },
+ },
+ },
+ {
+ "new line insertion",
+ `resource "aws_vpc" "name" {}`,
+ `resource "aws_vpc" "name" {
+}`,
+ filesystem.FileChanges{
+ &fileChange{
+ newText: `resource "aws_vpc" "name" {
+}`,
+ rng: hcl.Range{
+ Filename: "test.tf",
+ Start: hcl.Pos{Line: 1, Column: 1, Byte: 0},
+ End: hcl.Pos{Line: 1, Column: 29, Byte: 28},
+ },
+ },
+ },
+ },
+ {
+ "new line insertion at EOF",
+ `resource "aws_vpc" "name" {
+}
+`,
+ `resource "aws_vpc" "name" {
+}
+
+`,
+ filesystem.FileChanges{
+ &fileChange{
+ newText: "\n",
+ rng: hcl.Range{
+ Start: hcl.Pos{Line: 3, Column: 1, Byte: 30},
+ End: hcl.Pos{Line: 3, Column: 1, Byte: 30},
+ },
+ },
+ },
+ },
+ {
+ "line insertion",
+ `resource "aws_vpc" "name" {
+ attr1 = "one"
+
+ attr3 = "three"
+}`,
+ `resource "aws_vpc" "name" {
+ attr1 = "one"
+ attr2 = "two"
+ attr3 = "three"
+}`,
+ filesystem.FileChanges{
+ &fileChange{
+ newText: ` attr2 = "two"
+`,
+ rng: hcl.Range{
+ Filename: "test.tf",
+ Start: hcl.Pos{Line: 3, Column: 1, Byte: 44},
+ End: hcl.Pos{Line: 4, Column: 1, Byte: 45},
+ },
+ },
+ },
+ },
+ }
+
+ for i, tc := range testCases {
+ t.Run(fmt.Sprintf("%d-%s", i, tc.name), func(t *testing.T) {
+ linesBefore := source.MakeSourceLines("test.tf",
+ []byte(tc.beforeCfg))
+ linesAfter := source.MakeSourceLines("test.tf",
+ []byte(tc.afterCfg))
+
+ changes := diffLines("test.tf", linesBefore, linesAfter)
+
+ opts := cmp.Options{
+ cmp.AllowUnexported(fileChange{}),
+ cmpopts.IgnoreTypes(difflib.OpCode{}),
+ }
+
+ if diff := cmp.Diff(tc.expectedChanges, changes, opts...); diff != "" {
+ t.Fatalf("Changes don't match: %s", diff)
+ }
+ })
+ }
+}

internal/hcl/hcl.go

@@ -1,17 +1,13 @@
 package hcl
 
 import (
- "fmt"
-
- "github.com/hashicorp/hcl/v2"
  hcllib "github.com/hashicorp/hcl/v2"
  "github.com/hashicorp/hcl/v2/hclsyntax"
  "github.com/hashicorp/terraform-ls/internal/filesystem"
 )
 
 type File interface {
  BlockAtPosition(filesystem.FilePosition) (*hcllib.Block, hcllib.Pos, error)
- Diff([]byte) (filesystem.FileChanges, error)
 }
 
 type file struct {
@@ -49,36 +45,6 @@ func (f *file) BlockAtPosition(filePos filesystem.FilePosition) (*hcllib.Block,
  return b, pos, nil
 }
 
-func (f *file) Diff(target []byte) (filesystem.FileChanges, error) {
- var changes filesystem.FileChanges
-
- ast, _ := f.ast()
- body, ok := ast.Body.(*hclsyntax.Body)
- if !ok {
- return nil, fmt.Errorf("invalid configuration format: %T", ast.Body)
- }
-
- changes = append(changes, &fileChange{
- newText: target,
- rng: body.Range(),
- })
-
- return changes, nil
-}
-
-type fileChange struct {
- newText []byte
- rng hcl.Range
-}
-
-func (ch *fileChange) Text() string {
- return string(ch.newText)
-}
-
-func (ch *fileChange) Range() hcl.Range {
- return ch.rng
-}
-
 func (f *file) blockAtPosition(pos hcllib.Pos) (*hcllib.Block, error) {
  ast, _ := f.ast()