catch exceptions in casting constructors (#74)

* catch exceptions in casting constructors

* Fix the leaks

CHANGELOG.md

@@ -1,5 +1,10 @@
 # Changelog
 
+### [1.0.2]
+
+ - Upgrade ImageMagick to the latest 7.1.1-27 (git)
+ - Fix [#72](https://github.com/mmomtchev/magickwand.js/issues/72), exception in constructors used for implicit casting are not catchable
+
 ### [1.0.1] 2024-01-18
 
  - Update ImageMagick to 7.1.1-26

src/ImplicitCasting.i

@@ -18,10 +18,21 @@
     {
       // We apply the default std::string typemap - it parses
       // its argument in a local temporary $1
-      std::string *$1;
+      std::string *$1 = nullptr;
       $typemap(in, const std::string &);
       // Construct the object from this string
-      from_string_temp = $*ltype(*$1);
+      try {
+        // SWIG will automatically insert an exception handler in actions
+        // but this does not apply to typemaps - here we call ImageMagick code
+        // which can throw
+        from_string_temp = $*ltype(*$1);
+      } catch (const Magick::Exception &e) {
+        delete $1;
+        // SWIG_Raise is the language-independent macro which expands to
+        // the language-specific function call, it is available only in .i files
+        SWIG_NAPI_Raise(env, e.what());
+        SWIG_fail;
+      }
       // The string is not needed anymore
       delete $1;
     }

test/Color.shared.ts

@@ -76,6 +76,12 @@ export default function (
           .map((v) => Math.floor(v * 255).toString(16).padStart(2, '0')).join(''),
           '#ff7f0160');
       });
+
+      it('handling invalid color', () => {
+        assert.throws(() => {
+          new Color('invalid');
+        }, /unrecognized color `invalid'/);
+      });
     });
   });
 }

test/Image.shared.ts

@@ -45,6 +45,12 @@ export default function (
         // @ts-ignore
         assert.throws(() => new Image(null), /Illegal arguments for construction/);
       });
+
+      it('handling invalid color', () => {
+        assert.throws(() => {
+          new Image('100x100', 'invalid');
+        }, /unrecognized color `invalid'/);
+      });
     });
 
     describe('pixelColor', () => {