internal/lsp: minor refactoring for source.Identifier

Change-Id: Ia604f59d6229c2086fe63e73466de7489e1cda2d
Reviewed-on: https://go-review.googlesource.com/c/tools/+/189321
Run-TryBot: Rebecca Stambler <rstambler@golang.org>
Reviewed-by: Michael Matloob <matloob@golang.org>

internal/lsp/definition.go

@@ -27,7 +27,7 @@ func (s *Server) definition(ctx context.Context, params *protocol.TextDocumentPo
 	if err != nil {
 		return nil, err
 	}
-	ident, err := source.Identifier(ctx, view, f, rng.Start)
+	ident, err := source.Identifier(ctx, f, rng.Start)
 	if err != nil {
 		return nil, err
 	}
@@ -61,7 +61,7 @@ func (s *Server) typeDefinition(ctx context.Context, params *protocol.TextDocume
 	if err != nil {
 		return nil, err
 	}
-	ident, err := source.Identifier(ctx, view, f, rng.Start)
+	ident, err := source.Identifier(ctx, f, rng.Start)
 	if err != nil {
 		return nil, err
 	}

internal/lsp/hover.go

@@ -6,6 +6,7 @@ package lsp
 
 import (
 	"context"
+
 	"golang.org/x/tools/internal/lsp/protocol"
 	"golang.org/x/tools/internal/lsp/source"
 	"golang.org/x/tools/internal/span"
@@ -26,7 +27,7 @@ func (s *Server) hover(ctx context.Context, params *protocol.TextDocumentPositio
 	if err != nil {
 		return nil, err
 	}
-	ident, err := source.Identifier(ctx, view, f, identRange.Start)
+	ident, err := source.Identifier(ctx, f, identRange.Start)
 	if err != nil {
 		return nil, nil
 	}

internal/lsp/references.go

@@ -30,7 +30,7 @@ func (s *Server) references(ctx context.Context, params *protocol.ReferenceParam
 		return nil, err
 	}
 	// Find all references to the identifier at the position.
-	ident, err := source.Identifier(ctx, view, f, rng.Start)
+	ident, err := source.Identifier(ctx, f, rng.Start)
 	if err != nil {
 		return nil, err
 	}

internal/lsp/rename.go

@@ -27,7 +27,7 @@ func (s *Server) rename(ctx context.Context, params *protocol.RenameParams) (*pr
 	if err != nil {
 		return nil, err
 	}
-	ident, err := source.Identifier(ctx, view, f, rng.Start)
+	ident, err := source.Identifier(ctx, f, rng.Start)
 	if err != nil {
 		return nil, err
 	}

internal/lsp/source/completion_format.go

@@ -118,7 +118,7 @@ func (c *completer) item(cand candidate) (CompletionItem, error) {
 			log.Error(c.ctx, "declaration in a Go file", err, tag.Of("Label", item.Label))
 			goto Return
 		}
-		ident, err := Identifier(c.ctx, c.view, gof, declRange.Start)
+		ident, err := Identifier(c.ctx, gof, declRange.Start)
 		if err != nil {
 			log.Error(c.ctx, "no identifier", err, tag.Of("Name", obj.Name()))
 			goto Return

internal/lsp/source/identifier.go

@@ -47,25 +47,7 @@ func (i *IdentifierInfo) DeclarationRange() span.Range {
 
 // Identifier returns identifier information for a position
 // in a file, accounting for a potentially incomplete selector.
-func Identifier(ctx context.Context, view View, f GoFile, pos token.Pos) (*IdentifierInfo, error) {
-	if result, err := identifier(ctx, view, f, pos); err != nil || result != nil {
-		return result, err
-	}
-	// If the position is not an identifier but immediately follows
-	// an identifier or selector period (as is common when
-	// requesting a completion), use the path to the preceding node.
-	result, err := identifier(ctx, view, f, pos-1)
-	if result == nil && err == nil {
-		err = errors.Errorf("no identifier found")
-	}
-	return result, err
-}
-
-// identifier checks a single position for a potential identifier.
-func identifier(ctx context.Context, view View, f GoFile, pos token.Pos) (*IdentifierInfo, error) {
-	ctx, done := trace.StartSpan(ctx, "source.identifier")
-	defer done()
-
+func Identifier(ctx context.Context, f GoFile, pos token.Pos) (*IdentifierInfo, error) {
 	file, err := f.GetAST(ctx, ParseFull)
 	if file == nil {
 		return nil, err
@@ -74,6 +56,30 @@ func identifier(ctx context.Context, view View, f GoFile, pos token.Pos) (*Ident
 	if pkg == nil || pkg.IsIllTyped() {
 		return nil, errors.Errorf("pkg for %s is ill-typed", f.URI())
 	}
+	return findIdentifier(ctx, f, pkg, file, pos)
+}
+
+func findIdentifier(ctx context.Context, f GoFile, pkg Package, file *ast.File, pos token.Pos) (*IdentifierInfo, error) {
+	if result, err := identifier(ctx, f, pkg, file, pos); err != nil || result != nil {
+		return result, err
+	}
+	// If the position is not an identifier but immediately follows
+	// an identifier or selector period (as is common when
+	// requesting a completion), use the path to the preceding node.
+	result, err := identifier(ctx, f, pkg, file, pos-1)
+	if result == nil && err == nil {
+		err = errors.Errorf("no identifier found")
+	}
+	return result, err
+}
+
+// identifier checks a single position for a potential identifier.
+func identifier(ctx context.Context, f GoFile, pkg Package, file *ast.File, pos token.Pos) (*IdentifierInfo, error) {
+	ctx, done := trace.StartSpan(ctx, "source.identifier")
+	defer done()
+
+	var err error
+
 	// Handle import specs separately, as there is no formal position for a package declaration.
 	if result, err := importSpec(ctx, f, file, pkg, pos); result != nil || err != nil {
 		return result, err
@@ -157,7 +163,7 @@ func identifier(ctx context.Context, view View, f GoFile, pos token.Pos) (*Ident
 	if result.decl.rng, err = objToRange(ctx, f.FileSet(), result.decl.obj); err != nil {
 		return nil, err
 	}
-	if result.decl.node, err = objToNode(ctx, view, pkg.GetTypes(), result.decl.obj, result.decl.rng); err != nil {
+	if result.decl.node, err = objToNode(ctx, f.View(), pkg.GetTypes(), result.decl.obj, result.decl.rng); err != nil {
 		return nil, err
 	}
 	typ := pkg.GetTypesInfo().TypeOf(result.ident)

internal/lsp/source/source_test.go

@@ -395,7 +395,7 @@ func (r *runner) Definition(t *testing.T, data tests.Definitions) {
 			t.Fatalf("failed to get token for %s: %v", d.Src.URI(), err)
 		}
 		pos := tok.Pos(d.Src.Start().Offset())
-		ident, err := source.Identifier(ctx, r.view, f.(source.GoFile), pos)
+		ident, err := source.Identifier(ctx, f.(source.GoFile), pos)
 		if err != nil {
 			t.Fatalf("failed for %v: %v", d.Src, err)
 		}
@@ -468,7 +468,7 @@ func (r *runner) Reference(t *testing.T, data tests.References) {
 			t.Fatalf("failed to get token for %s: %v", src.URI(), err)
 		}
 		pos := tok.Pos(src.Start().Offset())
-		ident, err := source.Identifier(ctx, r.view, f.(source.GoFile), pos)
+		ident, err := source.Identifier(ctx, f.(source.GoFile), pos)
 		if err != nil {
 			t.Fatalf("failed for %v: %v", src, err)
 		}
@@ -519,7 +519,7 @@ func (r *runner) Rename(t *testing.T, data tests.Renames) {
 		}
 		pos := tok.Pos(spn.Start().Offset())
 
-		ident, err := source.Identifier(r.ctx, r.view, f.(source.GoFile), pos)
+		ident, err := source.Identifier(r.ctx, f.(source.GoFile), pos)
 		if err != nil {
 			t.Error(err)
 			continue