fix: Unwrap Failable type by handling failure

src/modules/function/invocation.rs

@@ -94,10 +94,19 @@ impl SyntaxModule<ParserMetadata> for FunctionInvocation {
                 }
             }
 
+            let types = self.args.iter().map(|e| e.get_type()).collect::<Vec<Type>>();
+            let var_names = self.args.iter().map(|e| e.is_var()).collect::<Vec<bool>>();
+            self.refs.clone_from(&function_unit.arg_refs);
+            (self.kind, self.variant_id) = handle_function_parameters(meta, self.id, function_unit.clone(), &types, &var_names, tok.clone())?;
+
             self.is_failable = function_unit.is_failable;
             if self.is_failable {
                 match syntax(meta, &mut self.failed) {
-                    Ok(_) => {},
+                    Ok(_) => {
+                        if let Type::Failable(t) = &self.kind {
+                            self.kind = *t.clone();
+                        }
+                    },
                     Err(Failure::Quiet(_)) => return error!(meta, tok => {
                         message: "This function can fail. Please handle the failure",
                         comment: "You can use '?' in the end to propagate the failure"
@@ -113,10 +122,7 @@ impl SyntaxModule<ParserMetadata> for FunctionInvocation {
                     meta.add_message(message);
                 }
             }
-            let types = self.args.iter().map(|e| e.get_type()).collect::<Vec<Type>>();
-            let var_names = self.args.iter().map(|e| e.is_var()).collect::<Vec<bool>>();
-            self.refs.clone_from(&function_unit.arg_refs);
-            (self.kind, self.variant_id) = handle_function_parameters(meta, self.id, function_unit, &types, &var_names, tok)?;
+
             Ok(())
         })
     }

src/tests/validity/failed_block_unwraps_failable_type.ab

@@ -0,0 +1,11 @@
+fun failable(): Num? {
+    if 0 > 5 {
+        fail 1
+    }
+
+    return 1
+}
+
+let a = failable() failed: echo "Failed"
+
+if a is Num: echo "Succeded"

src/tests/validity/failed_unwraps_failable_type.ab

@@ -0,0 +1,11 @@
+fun failable(): Num? {
+    if 0 > 5 {
+        fail 1
+    }
+
+    return 1
+}
+
+let a = failable() failed: echo "Failed"
+
+if a is Num: echo "Succeded"

src/tests/validity/unsafe_unwraps_failable_type.ab

@@ -0,0 +1,9 @@
+fun test(): Num? {
+    if 0 < 5 {
+        fail 1
+    }
+
+    return 42
+}
+
+if unsafe test() is Num: echo "Succeded"