refactoring: Decouple generic HCL parsing logic

This also helps keeping CompletionCandidate immutable
and allows passing around already "trimmed" candidates
as opposed to letting the lsp package handle the trimming.

internal/hcl/hcl.go

@@ -9,11 +9,6 @@ import (
 	"github.com/hashicorp/terraform-ls/internal/filesystem"
 )
 
-type File interface {
-	BlockTokensAtPosition(hcl.Pos) (hclsyntax.Tokens, error)
-	TokenAtPosition(hcl.Pos) (hclsyntax.Token, error)
-}
-
 type file struct {
 	filename string
 	content  []byte
@@ -25,13 +20,43 @@ type parsedFile struct {
 	Tokens hclsyntax.Tokens
 }
 
-func NewFile(f filesystem.File) File {
+type parsedBlock struct {
+	tokens hclsyntax.Tokens
+}
+
+func (pb *parsedBlock) Tokens() hclsyntax.Tokens {
+	return pb.tokens
+}
+
+func (pb *parsedBlock) TokenAtPosition(pos hcl.Pos) (hclsyntax.Token, error) {
+	for _, t := range pb.tokens {
+		if rangeContainsOffset(t.Range, pos.Byte) {
+			return t, nil
+		}
+	}
+
+	return hclsyntax.Token{}, &NoTokenFoundErr{pos}
+}
+
+func NewFile(f filesystem.File) TokenizedFile {
 	return &file{
 		filename: f.Filename(),
 		content:  []byte(f.Text()),
 	}
 }
 
+func NewTestFile(b []byte) TokenizedFile {
+	return &file{
+		filename: "/test.tf",
+		content:  b,
+	}
+}
+
+func NewTestBlock(b []byte) (TokenizedBlock, error) {
+	f := NewTestFile(b)
+	return f.BlockAtPosition(hcllib.InitialPos)
+}
+
 func (f *file) parse() (*parsedFile, error) {
 	if f.pf != nil {
 		return f.pf, nil
@@ -60,32 +85,42 @@ func (f *file) parse() (*parsedFile, error) {
 	return f.pf, nil
 }
 
-func (f *file) BlockTokensAtPosition(pos hcllib.Pos) (hclsyntax.Tokens, error) {
+func (f *file) PosInBlock(pos hcl.Pos) bool {
+	_, err := f.BlockAtPosition(pos)
+	if IsNoBlockFoundErr(err) {
+		return false
+	}
+
+	return true
+}
+
+func (f *file) BlockAtPosition(pos hcllib.Pos) (TokenizedBlock, error) {
 	pf, _ := f.parse()
 
 	body, ok := pf.Body.(*hclsyntax.Body)
 	if !ok {
-		return hclsyntax.Tokens{}, fmt.Errorf("unexpected body type (%T)", body)
+		return nil, fmt.Errorf("unexpected body type (%T)", body)
 	}
 	if body.SrcRange.Empty() && pos != hcllib.InitialPos {
-		return hclsyntax.Tokens{}, &InvalidHclPosErr{pos, body.SrcRange}
+		return nil, &InvalidHclPosErr{pos, body.SrcRange}
 	}
 	if !body.SrcRange.Empty() {
 		if posIsEqual(body.SrcRange.End, pos) {
-			return pf.Tokens, &NoBlockFoundErr{pos}
+			return nil, &NoBlockFoundErr{pos}
 		}
 		if !body.SrcRange.ContainsPos(pos) {
-			return hclsyntax.Tokens{}, &InvalidHclPosErr{pos, body.SrcRange}
+			return nil, &InvalidHclPosErr{pos, body.SrcRange}
 		}
 	}
 
 	for _, block := range body.Blocks {
 		if block.Range().ContainsPos(pos) {
-			return definitionTokens(tokensInRange(pf.Tokens, block.Range())), nil
+			dt := definitionTokens(tokensInRange(pf.Tokens, block.Range()))
+			return &parsedBlock{dt}, nil
 		}
 	}
 
-	return pf.Tokens, &NoBlockFoundErr{pos}
+	return nil, &NoBlockFoundErr{pos}
 }
 
 func (f *file) TokenAtPosition(pos hcllib.Pos) (hclsyntax.Token, error) {

internal/hcl/hcl_test.go

@@ -129,7 +129,7 @@ func TestFile_BlockAtPosition(t *testing.T) {
 			},
 			&InvalidHclPosErr{
 				Pos:     hcl.Pos{Line: -42, Column: -3, Byte: -46},
-				InRange: hcl.Range{Filename: "test.tf", Start: hcl.InitialPos, End: hcl.InitialPos},
+				InRange: hcl.Range{Filename: "/test.tf", Start: hcl.InitialPos, End: hcl.InitialPos},
 			},
 			nil,
 		},
@@ -143,7 +143,7 @@ func TestFile_BlockAtPosition(t *testing.T) {
 			},
 			&InvalidHclPosErr{
 				Pos:     hcl.Pos{Line: 42, Column: 3, Byte: 46},
-				InRange: hcl.Range{Filename: "test.tf", Start: hcl.InitialPos, End: hcl.InitialPos},
+				InRange: hcl.Range{Filename: "/test.tf", Start: hcl.InitialPos, End: hcl.InitialPos},
 			},
 			nil,
 		},
@@ -161,7 +161,7 @@ func TestFile_BlockAtPosition(t *testing.T) {
 			&InvalidHclPosErr{
 				Pos: hcl.Pos{Line: 42, Column: 3, Byte: 46},
 				InRange: hcl.Range{
-					Filename: "test.tf",
+					Filename: "/test.tf",
 					Start:    hcl.InitialPos,
 					End:      hcl.Pos{Column: 1, Line: 4, Byte: 20},
 				},
@@ -237,10 +237,9 @@ provider "aws" {
 
 	for i, tc := range testCases {
 		t.Run(fmt.Sprintf("%d-%s", i+1, tc.name), func(t *testing.T) {
-			fsFile := filesystem.NewFile("test.tf", []byte(tc.content))
-			f := NewFile(fsFile)
+			f := NewTestFile([]byte(tc.content))
 
-			tokens, err := f.BlockTokensAtPosition(tc.pos)
+			tBlock, err := f.BlockAtPosition(tc.pos)
 			if err != nil {
 				if tc.expectedErr == nil {
 					t.Fatal(err)
@@ -254,7 +253,7 @@ provider "aws" {
 				t.Fatalf("Expected error: %s", tc.expectedErr)
 			}
 
-			if diff := cmp.Diff(hclsyntax.Tokens(tc.expectedTokens), tokens, opts...); diff != "" {
+			if diff := cmp.Diff(hclsyntax.Tokens(tc.expectedTokens), tBlock.Tokens(), opts...); diff != "" {
 				t.Fatalf("Unexpected token difference: %s", diff)
 			}
 

internal/hcl/types.go

@@ -0,0 +1,17 @@
+package hcl
+
+import (
+	"github.com/hashicorp/hcl/v2"
+	"github.com/hashicorp/hcl/v2/hclsyntax"
+)
+
+type TokenizedFile interface {
+	BlockAtPosition(hcl.Pos) (TokenizedBlock, error)
+	TokenAtPosition(hcl.Pos) (hclsyntax.Token, error)
+	PosInBlock(hcl.Pos) bool
+}
+
+type TokenizedBlock interface {
+	TokenAtPosition(hcl.Pos) (hclsyntax.Token, error)
+	Tokens() hclsyntax.Tokens
+}

internal/lsp/completion.go

@@ -1,11 +1,12 @@
 package lsp
 
 import (
+	"github.com/hashicorp/hcl/v2"
 	"github.com/hashicorp/terraform-ls/internal/terraform/lang"
 	lsp "github.com/sourcegraph/go-lsp"
 )
 
-func CompletionList(candidates lang.CompletionCandidates, caps lsp.TextDocumentClientCapabilities) lsp.CompletionList {
+func CompletionList(candidates lang.CompletionCandidates, pos hcl.Pos, caps lsp.TextDocumentClientCapabilities) lsp.CompletionList {
 	snippetSupport := caps.Completion.CompletionItem.SnippetSupport
 	list := lsp.CompletionList{}
 
@@ -18,13 +19,13 @@ func CompletionList(candidates lang.CompletionCandidates, caps lsp.TextDocumentC
 	list.IsIncomplete = !candidates.IsComplete()
 	list.Items = make([]lsp.CompletionItem, len(cList))
 	for i, c := range cList {
-		list.Items[i] = CompletionItem(c, snippetSupport)
+		list.Items[i] = CompletionItem(c, pos, snippetSupport)
 	}
 
 	return list
 }
 
-func CompletionItem(candidate lang.CompletionCandidate, snippetSupport bool) lsp.CompletionItem {
+func CompletionItem(candidate lang.CompletionCandidate, pos hcl.Pos, snippetSupport bool) lsp.CompletionItem {
 	// TODO: deprecated / tags?
 
 	doc := ""
@@ -33,7 +34,6 @@ func CompletionItem(candidate lang.CompletionCandidate, snippetSupport bool) lsp
 		doc = c.Value()
 	}
 
-	r := candidate.PrefixRange()
 	if snippetSupport {
 		return lsp.CompletionItem{
 			Label:            candidate.Label(),
@@ -43,8 +43,8 @@ func CompletionItem(candidate lang.CompletionCandidate, snippetSupport bool) lsp
 			Documentation:    doc,
 			TextEdit: &lsp.TextEdit{
 				Range: lsp.Range{
-					Start: lsp.Position{Line: r.Start.Line - 1, Character: r.Start.Column - 1},
-					End:   lsp.Position{Line: r.End.Line - 1, Character: r.End.Column - 1},
+					Start: lsp.Position{Line: pos.Line - 1, Character: pos.Column - 1},
+					End:   lsp.Position{Line: pos.Line - 1, Character: pos.Column - 1},
 				},
 				NewText: candidate.Snippet(),
 			},
@@ -59,10 +59,10 @@ func CompletionItem(candidate lang.CompletionCandidate, snippetSupport bool) lsp
 		Documentation:    doc,
 		TextEdit: &lsp.TextEdit{
 			Range: lsp.Range{
-				Start: lsp.Position{Line: r.Start.Line - 1, Character: r.Start.Column - 1},
-				End:   lsp.Position{Line: r.End.Line - 1, Character: r.End.Column - 1},
+				Start: lsp.Position{Line: pos.Line - 1, Character: pos.Column - 1},
+				End:   lsp.Position{Line: pos.Line - 1, Character: pos.Column - 1},
 			},
-			NewText: candidate.Label(),
+			NewText: candidate.PlainText(),
 		},
 	}
 }