internal/lsp: make snippets private fields

Change-Id: I35d883196c7c3b35e14b49c0f5c779a91e72ce42
Reviewed-on: https://go-review.googlesource.com/c/tools/+/177177
Run-TryBot: Rebecca Stambler <rstambler@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Cottrell <iancottrell@google.com>

internal/lsp/completion.go

@@ -65,11 +65,7 @@ func toProtocolCompletionItems(candidates []source.CompletionItem, prefix string
 		}
 		insertText := candidate.InsertText
 		if insertTextFormat == protocol.SnippetTextFormat {
-			if usePlaceholders && candidate.PlaceholderSnippet != nil {
-				insertText = candidate.PlaceholderSnippet.String()
-			} else if candidate.Snippet != nil {
-				insertText = candidate.Snippet.String()
-			}
+			insertText = candidate.Snippet(usePlaceholders)
 		}
 		item := protocol.CompletionItem{
 			Label:  candidate.Label,

internal/lsp/source/completion.go

@@ -44,7 +44,7 @@ type CompletionItem struct {
 	//
 	//     foo(${1:})
 	//
-	Snippet *snippet.Builder
+	plainSnippet *snippet.Builder
 
 	// PlaceholderSnippet is the LSP snippet for the completion ite, containing
 	// placeholders. The LSP specification contains details about LSP snippets.
@@ -56,7 +56,21 @@ type CompletionItem struct {
 	//
 	//     foo(${1:a int}, ${2: b int}, ${3: c int})
 	//
-	PlaceholderSnippet *snippet.Builder
+	placeholderSnippet *snippet.Builder
+}
+
+// Snippet is a convenience function that determines the snippet that should be
+// used for an item, depending on if the callee wants placeholders or not.
+func (i *CompletionItem) Snippet(usePlaceholders bool) string {
+	if usePlaceholders {
+		if i.placeholderSnippet != nil {
+			return i.placeholderSnippet.String()
+		}
+	}
+	if i.plainSnippet != nil {
+		return i.plainSnippet.String()
+	}
+	return i.InsertText
 }
 
 type CompletionItemKind int

internal/lsp/source/completion_format.go

@@ -81,8 +81,8 @@ func (c *completer) item(obj types.Object, score float64) CompletionItem {
 		Detail:             detail,
 		Kind:               kind,
 		Score:              score,
-		Snippet:            plainSnippet,
-		PlaceholderSnippet: placeholderSnippet,
+		plainSnippet:       plainSnippet,
+		placeholderSnippet: placeholderSnippet,
 	}
 }
 
@@ -126,7 +126,7 @@ func (c *completer) formatBuiltin(obj types.Object, score float64) CompletionIte
 		params, _ := c.formatFieldList(decl.Type.Params)
 		results, writeResultParens := c.formatFieldList(decl.Type.Results)
 		item.Label, item.Detail = formatFunction(obj.Name(), params, results, writeResultParens)
-		item.Snippet, item.PlaceholderSnippet = c.functionCallSnippets(obj.Name(), params)
+		item.plainSnippet, item.placeholderSnippet = c.functionCallSnippets(obj.Name(), params)
 	case *types.TypeName:
 		if types.IsInterface(obj.Type()) {
 			item.Kind = InterfaceCompletionItem

internal/lsp/source/source_test.go

@@ -173,32 +173,22 @@ func (r *runner) checkCompletionSnippets(ctx context.Context, t *testing.T, data
 			}
 
 			wantCompletion := items[want.CompletionItem]
-			var gotItem *source.CompletionItem
+			var got *source.CompletionItem
 			for _, item := range list {
 				if item.Label == wantCompletion.Label {
-					gotItem = &item
+					got = &item
 					break
 				}
 			}
-
-			if gotItem == nil {
+			if got == nil {
 				t.Fatalf("%s: couldn't find completion matching %q", src.URI(), wantCompletion.Label)
 			}
 
-			var expected string
+			expected := want.PlainSnippet
 			if usePlaceholders {
 				expected = want.PlaceholderSnippet
-			} else {
-				expected = want.PlainSnippet
 			}
-			insertText := gotItem.InsertText
-			if usePlaceholders && gotItem.PlaceholderSnippet != nil {
-				insertText = gotItem.PlaceholderSnippet.String()
-			} else if gotItem.Snippet != nil {
-				insertText = gotItem.Snippet.String()
-			}
-
-			if expected != insertText {
+			if insertText := got.Snippet(usePlaceholders); expected != insertText {
 				t.Errorf("%s: expected snippet %q, got %q", src, expected, insertText)
 			}
 		}