raising error variable is not defined

Author: ppaska

src/evaluator/evaluator.ts

@@ -193,8 +193,13 @@ export class Evaluator {
         }
 
         if (node.type === "getSingleVar") {
+            const name = (node as GetSingleVarNode).name;
+
             const value = blockContext.blockScope.get((node as GetSingleVarNode).name);
-            return value === undefined ? null : value;
+            if(value === undefined){
+                throw new Error(`Variable ${name} is not defined.`);
+            }
+            return value;
         }
 
         if (node.type === "binOp") {

src/evaluator/evaluatorAsync.ts

@@ -200,8 +200,12 @@ export class EvaluatorAsync {
         }
 
         if (node.type === "getSingleVar") {
-            const value = blockContext.blockScope.get((node as GetSingleVarNode).name);
-            return value === undefined? null : value;
+            const name = (node as GetSingleVarNode).name;
+            const value = blockContext.blockScope.get(name);
+            if(value === undefined){
+                throw new Error(`Variable ${name} is not defined.`);
+            }
+            return value;
         }
 
         if (node.type === "binOp") {

src/interpreter.spec.ts

@@ -290,8 +290,8 @@ describe('Interpreter', () => {
   });
 
   it('chaining funcCall with null coelsing', () => {
-    expect(e.eval("p?.f()?.sdsd")).toBe(null);
-    expect(e.eval("p?.f()?.sdsd or 5")).toBe(5);
+    expect(e.eval("p={f: ()=>null}\np?.f()?.sdsd")).toBe(null);
+    expect(e.eval("p={f: ()=>null}\np?.f()?.sdsd or 5")).toBe(5);
   });
 
   it('comparison operations', () => {
@@ -323,10 +323,10 @@ describe('Interpreter', () => {
   });
 
   it('conditionals', async () => {
-    expect(await e.evaluate('x == null')).toBe(true)
-    expect(await e.evaluate('x?.p1?.p == null')).toBe(true)
-    expect(await e.evaluate('x != null and x.length >0')).toBe(false)
-    expect(await e.evaluate('x?.p1?.p != null and x.length >0')).toBe(false)
+    expect(await e.evaluate('x = null\nx == null')).toBe(true)
+    expect(await e.evaluate('x = null\nx?.p1?.p == null')).toBe(true)
+    expect(await e.evaluate('x = null\nx != null and x.length >0')).toBe(false)
+    expect(await e.evaluate('x = null\nx?.p1?.p != null and x.length >0')).toBe(false)
   });
 
   it('arithmetic + comparison', async () => {    

src/interpreter.ts

@@ -26,6 +26,10 @@ export class Interpreter {
         return new Interpreter();
     }
 
+    jsPythonInfo(){
+        return this.initialScope.jsPython();
+    }
+
     tokenize(script: string): Token[] {
         const tokenizer = new Tokenizer();
         return tokenizer.tokenize(script);