fix Cannot access null value from map

ethanblake4 · Oct 10, 2024 · 72b32b0 · 72b32b0
1 parent b06ed0d
commit 72b32b0
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Showing 2 changed files with 92 additions and 7 deletions.
diff --git a/lib/src/eval/runtime/ops/objects.dart b/lib/src/eval/runtime/ops/objects.dart
@@ -95,13 +95,23 @@ class InvokeDynamic implements EvcOp {
         runtime._prOffset = object.offset;
         return;
       }
-      final method = ((object as $Instance).$getProperty(runtime, _method)
-          as EvalFunction);
-      try {
-        runtime.returnValue = method.call(runtime, object, runtime.args.cast());
-      } catch (e) {
-        runtime.$throw(e);
+
+      if (object == null) {
+        object = $Null();
+      }
+
+      if (object is $Instance) {
+        final method = (object.$getProperty(runtime, _method) as EvalFunction);
+        try {
+          runtime.returnValue =
+              method.call(runtime, object, runtime.args.cast());
+        } catch (e) {
+          runtime.$throw(e);
+        }
+      } else {
+        runtime.returnValue = $null();
       }
+
       runtime.args = [];
       return;
     }
@@ -156,7 +166,14 @@ class CheckEq implements EvcOp {
         return;
       }
 
-      runtime.returnValue = v1 == v2;
+      if (v2 is $Value && v1 is! $Value) {
+        runtime.returnValue = v2.$value == v1;
+      } else if (v1 is $Value && v2 is! $Value) {
+        runtime.returnValue = v1.$value == v2;
+      } else {
+        runtime.returnValue = v1 == v2;
+      }
+
       return;
     }
   }

diff --git a/lib/src/eval/shared/stdlib/core/base.dart b/lib/src/eval/shared/stdlib/core/base.dart
@@ -520,3 +520,71 @@ class $String implements $Instance {
   @override
   int get hashCode => $value.hashCode;
 }
+
+/// dart_eval [$Instance] representation of a [Null]
+class $Null implements $Instance {
+  $Null() : _superclass = $Object(_Null());
+
+  static const $declaration = BridgeClassDef(
+      BridgeClassType(BridgeTypeRef(CoreTypes.nullType), isAbstract: true),
+      constructors: {},
+      methods: {
+        // Other Null methods defined in builtins.dart
+      },
+      wrap: true);
+
+  final $Instance _superclass;
+
+  @override
+  $Value? $getProperty(Runtime runtime, String identifier) {
+    try {
+      return _superclass.$getProperty(runtime, identifier);
+    } catch (e) {
+      return $Function((
+        Runtime runtime,
+        $Value? target,
+        List<$Value?> args,
+      ) {
+        return $null();
+      });
+    }
+  }
+
+  @override
+  void $setProperty(Runtime runtime, String identifier, $Value value) {}
+
+  @override
+  _Null get $reified => $value;
+
+  @override
+  bool operator ==(Object other) {
+    return identical(this, other) ||
+        other is $Null &&
+            runtimeType == other.runtimeType &&
+            $value == other.$value;
+  }
+
+  @override
+  int get hashCode => $value.hashCode;
+
+  @override
+  String toString() {
+    return '\$${$value}';
+  }
+
+  @override
+  int $getRuntimeType(Runtime runtime) =>
+      runtime.lookupType(CoreTypes.nullType);
+
+  @override
+  get $value => _Null();
+}
+
+@pragma("vm:entry-point")
+class _Null extends Object {
+  String toString() => "null";
+
+  dynamic noSuchMethod(Invocation invocation) {
+    print("_Null.noSuchMethod(): $invocation");
+  }
+}