jspython-dev
diff --git a/‎index.html
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+2-1Lines changed: 2 additions & 1 deletion b/‎index.html
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+2-1Lines changed: 2 additions & 1 deletion
diff --git a/‎package.json
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+1-1Lines changed: 1 addition & 1 deletion b/‎package.json
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+1-1Lines changed: 1 addition & 1 deletion
diff --git a/‎src/eval/eval.expression.ts
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+5-2Lines changed: 5 additions & 2 deletions b/‎src/eval/eval.expression.ts
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+5-2Lines changed: 5 additions & 2 deletions
diff --git a/‎src/interpreter.spec.ts
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+15Lines changed: 15 additions & 0 deletions b/‎src/interpreter.spec.ts
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+15Lines changed: 15 additions & 0 deletions
@@ -28,7 +28,8 @@
   <div class="container">
     <h4>JSPython development console</h4>
     <div id="editor">
-"".trim().length
+x = {}
+x["prop1"]      
     </div>
     <button onclick="runInterpreter()">Run</button>
     <textarea id="result"></textarea>
 
@@ -1,6 +1,6 @@
 {
   "name": "jspython-interpreter",
-  "version": "0.1.5",
+  "version": "0.1.6",
   "description": "JSPython is a javascript implementation of Python language that runs within web browser or NodeJS environment",
   "keywords": [
     "python",
 
@@ -266,7 +266,10 @@ export class EvalExpression {
                 } else {
                     const tokens = this.splitParameterToken(ind);
                     const pName = this.evalExpression(context, tokens)
-                    return obj[pName];
+                    
+                    // if it is undefined means does not exists. So, we have to return null, but still gracely handle 0 (zero)
+                    const v = obj[pName]                    
+                    return v !== undefined? v : null;
                 }
 
             }
@@ -279,7 +282,7 @@ export class EvalExpression {
         } else {
             const value = getValue(context.blockScope, token);
             if (value === undefined) {
-                throw Error(`Can't resolve property '${token}' of undefined object`);
+                throw Error(`Unknown symbol '${token}'`);
             }
             return value;
         }
 
@@ -1482,6 +1482,21 @@ describe('Interpreter', () => {
 
   })
 
+  it('should return NULL gracely', async () => {
+    expect(await e.evaluate(`
+        x = {}
+        x["prop1"]`)).toBe(null);
+    
+    // has to be 0
+    expect(await e.evaluate(`
+        x = {prop1: 0}
+        x["prop1"]`)).toBe(0);
+
+    expect(await e.evaluate(`
+        x = {prop1: null}
+        x["prop1"]`)).toBe(null);
+  });
+
   it('subset of dynamic', async () => {
     expect(await e.evaluate(`
 issue = {}
Original file line number	Diff line number	Diff line change
`@@ -1,6 +1,6 @@`
`1`	`1`	`{`
`2`	`2`	`"name": "jspython-interpreter",`
`3`		`- "version": "0.1.5",`
	`3`	`+ "version": "0.1.6",`
`4`	`4`	`"description": "JSPython is a javascript implementation of Python language that runs within web browser or NodeJS environment",`
`5`	`5`	`"keywords": [`
`6`	`6`	`"python",`
Original file line number	Diff line number	Diff line change
`@@ -266,7 +266,10 @@ export class EvalExpression {`
`266`	`266`	`} else {`
`267`	`267`	`const tokens = this.splitParameterToken(ind);`
`268`	`268`	`const pName = this.evalExpression(context, tokens)`
`269`		`- return obj[pName];`
	`269`	`+`
	`270`	`+ // if it is undefined means does not exists. So, we have to return null, but still gracely handle 0 (zero)`
	`271`	`+ const v = obj[pName]`
	`272`	`+ return v !== undefined? v : null;`
`270`	`273`	`}`
`271`	`274`
`272`	`275`	`}`
`@@ -279,7 +282,7 @@ export class EvalExpression {`
`279`	`282`	`} else {`
`280`	`283`	`const value = getValue(context.blockScope, token);`
`281`	`284`	`if (value === undefined) {`
`282`		- throw Error(`Can't resolve property '${token}' of undefined object`);
	`285`	+ throw Error(`Unknown symbol '${token}'`);
`283`	`286`	`}`
`284`	`287`	`return value;`
`285`	`288`	`}`