[Linter] Fix super index type and handle "object or string" indexing correctly.

linter/internal/types/build_graph.go

@@ -234,7 +234,7 @@ func calcTP(node ast.Node, varAt map[ast.Node]*common.Variable, g *typeGraph) ty
 		// no recursion yet
 		return tpRef(anyObjectType)
 	case *ast.SuperIndex:
-		return tpRef(anyObjectType)
+		return tpRef(anyType)
 	case *ast.InSuper:
 		return tpRef(boolType)
 	case *ast.Function:

linter/internal/types/check.go

@@ -55,8 +55,8 @@ func check(node ast.Node, typeOf exprTypes, ec *common.ErrCollector) {
 			if !indexType.Number {
 				ec.StaticErr("Indexed value is assumed to be "+assumedType+", but index is not a number", node.Loc())
 			}
-		} else if !targetType.Array() {
+		} else if !targetType.Array() && !targetType.String {
-			// It's not an array so it must be an object
+			// It's not an array or a string so it must be an object
 			if !indexType.String {
 				ec.StaticErr("Indexed value is assumed to be an object, but index is not a string", node.Loc())
 			}

linter/testdata/object_or_array_indexing.jsonnet

@@ -0,0 +1,5 @@
+local foo = if true then {"foo": "bar"} else ["f", "o", "o"];
+[
+    foo[0],
+    foo["foo"]
+]

linter/testdata/object_or_string_indexing.jsonnet

@@ -0,0 +1,5 @@
+local foo = if true then {"foo": "bar"} else "foo";
+[
+    foo[0],
+    foo["foo"]
+]

linter/testdata/super_index_array.jsonnet

@@ -0,0 +1,4 @@
+local foo = { config: [{ x: 'y' }] };
+foo {
+  config: [super.config[0] { a: 'b' }],
+}