Add proper support for structs and inout params in blocks

Also allows passing strings to Instance.methodForSelector, and fixes an infinite recursion issue when trying to call a nonexistant method (e.g. -description or -debugDescription) on an instance of a class which implements neither -description or -debugDescription.

Author: lukaskollmer

examples/range.js

@@ -0,0 +1,45 @@
+const objc = require('../');
+const ref = require('ref-napi');
+
+objc.import('AppKit');
+
+const {
+    NSString,
+    NSMutableString,
+    NSAttributedString,
+    NSMutableAttributedString,
+    NSLinkAttributeName
+} = objc;
+
+const { id, NSRange } = objc.types;
+
+
+let attrString = NSMutableAttributedString.new();
+attrString.appendAttributedString_(NSAttributedString.alloc().initWithString_attributes_(
+    'abc', {
+        [NSLinkAttributeName]: 'https://example.com'
+    }
+));
+attrString.appendAttributedString_(NSAttributedString.alloc().initWithString_attributes_(
+    'def', {
+        [NSLinkAttributeName]: 'https://example.de'
+    }
+));
+
+console.log(attrString);
+
+
+let range = NSRange.new(0, attrString.length());
+console.log(range);
+
+
+let block = new objc.Block((arg0, arg1, arg2) => {
+    const attrs = objc.wrap(arg0);
+    const range = arg1;
+    console.log(`block called w/ args attrs: ${attrs}, range: ${[arg1.location, arg1.length]}, stop: ${arg2.deref()}`);
+    //ref.set(arg2, 0, 1); // uncomment this to have it stop iterating after the first range.
+    return;
+}, objc.types.void, [id, NSRange, ref.refType(objc.types.char)]);
+
+attrString.enumerateAttributesInRange_options_usingBlock_(range, 0, block);
+

src/instance.js

@@ -28,6 +28,9 @@ class Instance {
   }
 
   methodForSelector(selector) {
+    if (typeof selector === 'string') {
+      selector = new Selector(selector);
+    }
     if (this.type === 'class') {
       return runtime.class_getClassMethod(this.__ptr, selector.__ptr);
     }
@@ -135,7 +138,24 @@ class Instance {
     if (this.__ptr === null || this.__ptr.isNull()) {
       return '(null)';
     }
-    return this.call('debugDescription').UTF8String(); // eslint-disable-line new-cap
+    if (this.respondsToSelector('description')) {
+      return this.call('description').UTF8String(); // eslint-disable-line new-cap
+    } else if (this.respondsToSelector('debugDescription')) {
+      return this.call('debugDescription').UTF8String(); // eslint-disable-line new-cap
+    } else if (this.respondsToSelector('class')) {
+      let classname = runtime.class_getName(this.call('class'));
+      return `<${classname} ${this.__ptr}>`;
+    } else if (this.type === 'instance') {
+      let classname;
+      if (this.type === 'instance') {
+        classname = runtime.class_getName(runtime.object_getClass(this.__ptr));
+      } else {
+        classname = runtime.class_getName(this.__ptr);
+      }
+      return `<${classname} ${this.__ptr}>`;
+    } else {
+      return `objc.Instance(type: ${this.type}, __ptr: ${this.__ptr})`;
+    }
   }
 
   toString() {
@@ -157,6 +177,7 @@ class Instance {
   }
 
   static alloc() {
+    // TODO is this zero-initialised? (probably will otherwise try to fuck up rhe refcount, right?)
     return new InstanceProxy(new Instance(ref.alloc(inoutType)));
   }
 

src/structs.js

@@ -2,6 +2,7 @@ const ref = require('ref-napi')
 const struct = require('ref-struct-di')(ref);
 
 const CompoundInit = Symbol('structs.CompoundInit');
+const IsStructSymbol = Symbol();
 const structs = {};
 
 const createStructInitializer = (name, StructType) => {
@@ -31,7 +32,7 @@ const createStructInitializer = (name, StructType) => {
 
     return retval;
   };
-
+  StructType[IsStructSymbol] = true;
   return StructType;
 };
 
@@ -49,5 +50,7 @@ module.exports = {
     return createStructInitializer(name, type);
   },
 
-  getStructType: name => structs[name]
+  getStructType: name => structs[name],
+
+  isStructFn: obj => obj[IsStructSymbol] === true
 };

src/type-encodings.js

@@ -254,6 +254,9 @@ module.exports = {
     } else if (typeof type === 'object') {
       return type;
     }
+    if (structs.isStructFn(type)) {
+      return type;
+    }
 
     throw new TypeError(`Unable to coerce type from ${type}`);
   }

test.js

@@ -636,6 +636,52 @@ test('Blocks: objc.Block passes for full block type encoding', t => {
 });
 
 
+test('Blocks: Block w/ struct parameter and inout BOOL*', t => {
+  const ref = require('ref-napi');
+  objc.import('AppKit');
+  const { NSAttributedString, NSMutableAttributedString, NSLinkAttributeName } = objc;
+  const { id, NSRange } = objc.types;
+  let attrString = NSMutableAttributedString.new();
+  attrString.appendAttributedString_(NSAttributedString.alloc().initWithString_attributes_(
+    'abc', {
+      [NSLinkAttributeName]: 'https://example.com'
+    }
+  ));
+  attrString.appendAttributedString_(NSAttributedString.alloc().initWithString_attributes_(
+    'def', {
+      [NSLinkAttributeName]: 'https://example.de'
+    }
+  ));
+  attrString.appendAttributedString_(NSAttributedString.alloc().initWithString_attributes_(
+    'ghi', {
+      [NSLinkAttributeName]: 'https://example.net'
+    }
+  ));
+  t.is(attrString.description().UTF8String(), `abc{
+    NSLink = "https://example.com";
+}def{
+    NSLink = "https://example.de";
+}ghi{
+    NSLink = "https://example.net";
+}`);
+
+  let blockArgs = [];
+  let block = new objc.Block((arg0, arg1, arg2) => {
+    const attrs = objc.wrap(arg0);
+    const range = arg1;
+    blockArgs.push([objc.js(attrs), {location: range.location, length: range.length}]);
+    if (range.location === 3 && range.length === 3) {
+      ref.set(arg2, 0, 1); // uncomment this to have it stop iterating after the first range.
+    }
+    return;
+  }, objc.types.void, [id, NSRange, ref.refType(objc.types.char)]);
+  attrString.enumerateAttributesInRange_options_usingBlock_(NSRange.new(0, attrString.length()), 0, block);
+  t.deepEqual(blockArgs, [ // We expect the third pair to be missing, which tells us that stopping the iteration early by setting the *stop param worked.
+    [{NSLink: 'https://example.com'}, { location: 0, length: 3 }],
+    [{NSLink: 'https://example.de' }, { location: 3, length: 3 }]
+  ]);
+})
+
 /*
 Iterators
 */