Completion from dollar sign: Basic case (#79)

Closes #4

Also:
- Sort the list of suggestions by label
- Ignore lines ending with , or ;. This happens when a user is replacing an index in an existing line (refactoring, etc)

Author: julienduchesne

pkg/server/completion.go

@@ -2,6 +2,7 @@ package server
 
 import (
 	"context"
+	"sort"
 	"strings"
 
 	"github.com/google/go-jsonnet"
@@ -59,6 +60,7 @@ func getCompletionLine(fileContent string, position protocol.Position) string {
 func (s *Server) completionFromStack(line string, stack *nodestack.NodeStack, vm *jsonnet.VM) []protocol.CompletionItem {
 	lineWords := strings.Split(line, " ")
 	lastWord := lineWords[len(lineWords)-1]
+	lastWord = strings.TrimRight(lastWord, ",;") // Ignore trailing commas and semicolons, they can present when someone is modifying an existing line
 
 	indexes := strings.Split(lastWord, ".")
 	firstIndex, indexes := indexes[0], indexes[1:]
@@ -103,6 +105,8 @@ func (s *Server) completionFromStack(line string, stack *nodestack.NodeStack, vm
 				ref, _ := processing.FindVarReference(targetVar, vm)
 
 				switch ref := ref.(type) {
+				case *ast.Self: // This case catches `$` references (it's set as a self reference on the root object)
+					objectsToSearch = processing.FindTopLevelObjects(nodestack.NewNodeStack(stack.From), vm)
 				case *ast.DesugaredObject:
 					objectsToSearch = []*ast.DesugaredObject{ref}
 				case *ast.Import:
@@ -188,6 +192,10 @@ func createCompletionItemsFromObjects(objects []*ast.DesugaredObject, firstIndex
 		}
 	}
 
+	sort.Slice(items, func(i, j int) bool {
+		return items[i].Label < items[j].Label
+	})
+
 	return items
 }
 

pkg/server/completion_test.go

@@ -285,6 +285,52 @@ func TestCompletion(t *testing.T) {
 				},
 			},
 		},
+		{
+			name:            "autocomplete dollar sign",
+			filename:        "testdata/goto-dollar-simple.jsonnet",
+			replaceString:   "test: $.attribute,",
+			replaceByString: "test: $.",
+			expected: protocol.CompletionList{
+				IsIncomplete: false,
+				Items: []protocol.CompletionItem{
+					{
+						Label:      "attribute",
+						Kind:       protocol.FieldCompletion,
+						Detail:     "$.attribute",
+						InsertText: "attribute",
+					},
+					{
+						Label:      "attribute2",
+						Kind:       protocol.FieldCompletion,
+						Detail:     "$.attribute2",
+						InsertText: "attribute2",
+					},
+				},
+			},
+		},
+		{
+			name:            "autocomplete dollar sign, end with comma",
+			filename:        "testdata/goto-dollar-simple.jsonnet",
+			replaceString:   "test: $.attribute,",
+			replaceByString: "test: $.,",
+			expected: protocol.CompletionList{
+				IsIncomplete: false,
+				Items: []protocol.CompletionItem{
+					{
+						Label:      "attribute",
+						Kind:       protocol.FieldCompletion,
+						Detail:     "$.attribute",
+						InsertText: "attribute",
+					},
+					{
+						Label:      "attribute2",
+						Kind:       protocol.FieldCompletion,
+						Detail:     "$.attribute2",
+						InsertText: "attribute2",
+					},
+				},
+			},
+		},
 	}
 	for _, tc := range testCases {
 		t.Run(tc.name, func(t *testing.T) {