Basic go-to-definition inside functions (#63)

When processing the index list, the language server will now go through function bodies to find fields
This will only occur when the function's body is directly a DesugaredObject
This doesn't support all cases. I will probably have to add more, I have already identified cases which are even more complex that do not work yet, but this is a good first step

pkg/ast_processing/find_field.go

@@ -2,6 +2,7 @@ package ast_processing
 
 import (
 	"fmt"
+	"reflect"
 	"strings"
 
 	"github.com/google/go-jsonnet"
@@ -68,8 +69,13 @@ func FindRangesFromIndexList(stack *nodestack.NodeStack, indexList []string, vm
 			tempStack := nodestack.NewNodeStack(bodyNode)
 			indexList = append(tempStack.BuildIndexList(), indexList...)
 			return FindRangesFromIndexList(stack, indexList, vm)
+		case *ast.Function:
+			// If the function's body is an object, it means we can look for indexes within the function
+			if funcBody, ok := bodyNode.Body.(*ast.DesugaredObject); ok {
+				foundDesugaredObjects = append(foundDesugaredObjects, funcBody)
+			}
 		default:
-			return nil, fmt.Errorf("unexpected node type when finding bind for '%s'", start)
+			return nil, fmt.Errorf("unexpected node type when finding bind for '%s': %s", start, reflect.TypeOf(bind.Body))
 		}
 	}
 	var ranges []ObjectRange
@@ -98,14 +104,29 @@ func FindRangesFromIndexList(stack *nodestack.NodeStack, indexList []string, vm
 			return nil, err
 		}
 
-		for _, fieldNode := range fieldNodes {
+		i := 0
+		for i < len(fieldNodes) {
+			fieldNode := fieldNodes[i]
 			switch fieldNode := fieldNode.(type) {
+			case *ast.Apply:
+				// Add the target of the Apply to the list of field nodes to look for
+				// The target is a function and will be found by findVarReference on the next loop
+				fieldNodes = append(fieldNodes, fieldNode.Target)
 			case *ast.Var:
 				varReference, err := findVarReference(fieldNode, vm)
 				if err != nil {
 					return nil, err
 				}
-				foundDesugaredObjects = append(foundDesugaredObjects, varReference.(*ast.DesugaredObject))
+				// If the reference is an object, add it directly to the list of objects to look in
+				if varReference, ok := varReference.(*ast.DesugaredObject); ok {
+					foundDesugaredObjects = append(foundDesugaredObjects, varReference)
+				}
+				// If the reference is a function, and the body of that function is an object, add it to the list of objects to look in
+				if varReference, ok := varReference.(*ast.Function); ok {
+					if funcBody, ok := varReference.Body.(*ast.DesugaredObject); ok {
+						foundDesugaredObjects = append(foundDesugaredObjects, funcBody)
+					}
+				}
 			case *ast.DesugaredObject:
 				stack.Push(fieldNode)
 				foundDesugaredObjects = append(foundDesugaredObjects, findDesugaredObjectFromStack(stack))
@@ -123,6 +144,7 @@ func FindRangesFromIndexList(stack *nodestack.NodeStack, indexList []string, vm
 				newObjs := findTopLevelObjectsInFile(vm, filename, string(fieldNode.Loc().File.DiagnosticFileName))
 				foundDesugaredObjects = append(foundDesugaredObjects, newObjs...)
 			}
+			i++
 		}
 	}
 

pkg/nodestack/nodestack.go

@@ -55,6 +55,10 @@ func (s *NodeStack) BuildIndexList() []string {
 	for !s.IsEmpty() {
 		curr := s.Pop()
 		switch curr := curr.(type) {
+		case *ast.Apply:
+			if target, ok := curr.Target.(*ast.Var); ok {
+				indexList = append(indexList, string(target.Id))
+			}
 		case *ast.SuperIndex:
 			s.Push(curr.Index)
 			indexList = append(indexList, "super")

pkg/server/definition_test.go

@@ -739,6 +739,36 @@ var definitionTestCases = []definitionTestCase{
 			},
 		}},
 	},
+	{
+		name:     "goto field through function",
+		filename: "testdata/goto-functions-advanced.libsonnet",
+		position: protocol.Position{Line: 6, Character: 46},
+		results: []definitionResult{{
+			targetRange: protocol.Range{
+				Start: protocol.Position{Line: 2, Character: 2},
+				End:   protocol.Position{Line: 2, Character: 12},
+			},
+			targetSelectionRange: protocol.Range{
+				Start: protocol.Position{Line: 2, Character: 2},
+				End:   protocol.Position{Line: 2, Character: 6},
+			},
+		}},
+	},
+	{
+		name:     "goto field through function-created object",
+		filename: "testdata/goto-functions-advanced.libsonnet",
+		position: protocol.Position{Line: 8, Character: 52},
+		results: []definitionResult{{
+			targetRange: protocol.Range{
+				Start: protocol.Position{Line: 2, Character: 2},
+				End:   protocol.Position{Line: 2, Character: 12},
+			},
+			targetSelectionRange: protocol.Range{
+				Start: protocol.Position{Line: 2, Character: 2},
+				End:   protocol.Position{Line: 2, Character: 6},
+			},
+		}},
+	},
 }
 
 func TestDefinition(t *testing.T) {
@@ -837,7 +867,7 @@ func TestDefinitionFail(t *testing.T) {
 			name:     "goto range index fails",
 			filename: "testdata/goto-local-function.libsonnet",
 			position: protocol.Position{Line: 15, Character: 57},
-			expected: fmt.Errorf("unexpected node type when finding bind for 'ports'"),
+			expected: fmt.Errorf("unexpected node type when finding bind for 'ports': *ast.Apply"),
 		},
 		{
 			name:     "goto super fails as no LHS object exists",

pkg/server/testdata/goto-functions-advanced.libsonnet

@@ -0,0 +1,10 @@
+local myfunc(arg1, arg2) = {
+  arg1: arg1,
+  arg2: arg2,
+};
+
+{
+  accessThroughFunc: myfunc('test', 'test').arg2,
+  funcCreatedObj: myfunc('test', 'test'),
+  accesThroughFuncCreatedObj: self.funcCreatedObj.arg2,
+}