Reduce null safety issues in Statement and Expression subclasses

src/bscPlugin/hover/HoverProcessor.ts

@@ -1,4 +1,3 @@
-import { SourceNode } from 'source-map';
 import { isBrsFile, isFunctionType, isXmlFile } from '../../astUtils/reflection';
 import type { BrsFile } from '../../files/BrsFile';
 import type { XmlFile } from '../../files/XmlFile';
@@ -67,7 +66,7 @@ export class HoverProcessor {
             //find a constant with this name
             const constant = scope?.getConstFileLink(fullName, containingNamespace);
             if (constant) {
-                const constantValue = new SourceNode(null, null, null, constant.item.value.transpile(new BrsTranspileState(file))).toString();
+                const constantValue = util.sourceNodeFromTranspileResult(null, null, null, constant.item.value.transpile(new BrsTranspileState(file))).toString();
                 return {
                     contents: this.buildContentsWithDocs(fence(`const ${constant.item.fullName} = ${constantValue}`), constant.item.tokens.const),
                     range: token.range

src/files/BrsFile.ts

@@ -1238,15 +1238,15 @@ export class BrsFile {
     /**
      * Determine if the callee (i.e. function name) is a known function declared on the given namespace.
      */
-    public calleeIsKnownNamespaceFunction(callee: Expression, namespaceName: string) {
+    public calleeIsKnownNamespaceFunction(callee: Expression, namespaceName: string | undefined) {
         //if we have a variable and a namespace
         if (isVariableExpression(callee) && namespaceName) {
             let lowerCalleeName = callee?.name?.text?.toLowerCase();
             if (lowerCalleeName) {
                 let scopes = this.program.getScopesForFile(this);
                 for (let scope of scopes) {
                     let namespace = scope.namespaceLookup.get(namespaceName.toLowerCase());
-                    if (namespace.functionStatements[lowerCalleeName]) {
+                    if (namespace?.functionStatements[lowerCalleeName]) {
                         return true;
                     }
                 }
@@ -1477,7 +1477,7 @@ export class BrsFile {
         let transpileResult: SourceNode | undefined;
 
         if (this.needsTranspiled) {
-            transpileResult = new SourceNode(null, null, state.srcPath, this.ast.transpile(state));
+            transpileResult = util.sourceNodeFromTranspileResult(null, null, state.srcPath, this.ast.transpile(state));
         } else if (this.program.options.sourceMap) {
             //emit code as-is with a simple map to the original file location
             transpileResult = util.simpleMap(state.srcPath, this.fileContents);
@@ -1506,7 +1506,7 @@ export class BrsFile {
     public getTypedef() {
         const state = new BrsTranspileState(this);
         const typedef = this.ast.getTypedef(state);
-        const programNode = new SourceNode(null, null, this.srcPath, typedef);
+        const programNode = util.sourceNodeFromTranspileResult(null, null, this.srcPath, typedef);
         return programNode.toString();
     }
 

src/files/XmlFile.ts

@@ -505,7 +505,8 @@ export class XmlFile {
             //temporarily add the missing imports as script tags
             this.ast.component.scripts = publishableScripts;
 
-            transpileResult = new SourceNode(null, null, state.srcPath, this.parser.ast.transpile(state));
+
+            transpileResult = util.sourceNodeFromTranspileResult(null, null, state.srcPath, this.parser.ast.transpile(state));
 
             //restore the original scripts array
             this.ast.component.scripts = originalScripts;

src/interfaces.ts

@@ -461,10 +461,17 @@ export interface SemanticToken {
 }
 
 export interface TypedefProvider {
-    getTypedef(state: TranspileState): Array<SourceNode | string>;
+    getTypedef(state: TranspileState): TranspileResult;
 }
 
-export type TranspileResult = Array<(string | SourceNode)>;
+export type TranspileResult = Array<(string | SourceNode | TranspileResult)>;
+
+/**
+ * This is the type that the SourceNode class is declared as taking in its constructor.
+ * The actual type that SourceNode accepts is the more permissive TranspileResult, but
+ * we need to use this declared type for some type casts.
+ */
+export type FlattenedTranspileResult = Array<string | SourceNode>;
 
 export type FileResolver = (srcPath: string) => string | undefined | Thenable<string | undefined> | void;
 

src/parser/AstNode.ts

@@ -16,7 +16,7 @@ export abstract class AstNode {
     /**
      *  The starting and ending location of the node.
      */
-    public abstract range: Range;
+    public abstract range: Range | undefined;
 
     public abstract transpile(state: BrsTranspileState): TranspileResult;
 

src/parser/BrsTranspileState.ts

@@ -22,7 +22,7 @@ export class BrsTranspileState extends TranspileState {
      * Used to assist blocks in knowing when to add a comment statement to the same line as the first line of the parent
      */
     lineage = [] as Array<{
-        range: Range;
+        range?: Range;
     }>;
 
     /**