foreign_function: better error messages when a type's "set()" functio…

…n throws Part of #78.
node-ffi · Oct 5, 2012 · 12c7090 · 12c7090
1 parent 2a4ea60
commit 12c7090
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Showing 2 changed files with 42 additions and 11 deletions.
diff --git a/lib/_foreign_function.js b/lib/_foreign_function.js
@@ -42,11 +42,17 @@ function ForeignFunction (cif, funcPtr, returnType, argTypes) {
       , argsList = new Buffer(argsArraySize)
 
     // write arguments to storage areas
-    for (var i = 0; i < numArgs; i++) {
+    var i, argType, val, valPtr
-      var argType = argTypes[i]
+    try {
-        , val = arguments[i]
+      for (i = 0; i < numArgs; i++) {
-      var valPtr = ref.alloc(argType, val)
+        argType = argTypes[i]
-      argsList.writePointer(valPtr, i * POINTER_SIZE)
+        val = arguments[i]
+        valPtr = ref.alloc(argType, val)
+        argsList.writePointer(valPtr, i * POINTER_SIZE)
+      }
+    } catch (e) {
+      e.message = 'error setting argument ' + i + ' - ' + e.message
+      throw e
     }
 
     // invoke the `ffi_call()` function
@@ -80,12 +86,17 @@ function ForeignFunction (cif, funcPtr, returnType, argTypes) {
     var argsList = new Buffer(argsArraySize)
 
     // write arguments to storage areas
-    for (var i = 0; i < numArgs; i++) {
+    var i, argType, val, valPtr
-      var argType = argTypes[i]
+    try {
-      var val = arguments[i]
+      for (i = 0; i < numArgs; i++) {
-
+        argType = argTypes[i]
-      var valPtr = ref.alloc(argType, val)
+        val = arguments[i]
-      argsList.writePointer(valPtr, i * POINTER_SIZE)
+        valPtr = ref.alloc(argType, val)
+        argsList.writePointer(valPtr, i * POINTER_SIZE)
+      }
+    } catch (e) {
+      e.message = 'error setting argument ' + i + ' - ' + e.message
+      return process.nextTick(callback.bind(null, e));
     }
 
     // invoke the `ffi_call()` function asynchronously

diff --git a/test/foreign_function.js b/test/foreign_function.js
@@ -28,6 +28,14 @@ describe('ForeignFunction', function () {
     assert.equal(1234, abs(-1234))
   })
 
+  it('should throw an Error with a meaningful message when type\'s `set()` throws', function () {
+    var _abs = bindings.abs
+    var abs = ffi.ForeignFunction(_abs, 'int', [ 'int' ])
+    assert.throws(function () {
+      abs('a string?!?!')
+    }, /error setting argument 0/)
+  })
+
   it('should call the static "atoi" bindings', function () {
     var _atoi = bindings.atoi
     var atoi = ffi.ForeignFunction(_atoi, 'int', [ 'string' ])
@@ -163,6 +171,18 @@ describe('ForeignFunction', function () {
       })
     })
 
+    it('should invoke the callback with an Error with a meaningful message when type\'s `set()` throws', function (done) {
+      var _abs = bindings.abs
+      var abs = ffi.ForeignFunction(_abs, 'int', [ 'int' ])
+
+      abs.async('a string!?!?', function (err, res) {
+          assert(err)
+          assert(/error setting argument 0/.test(err.message))
+          assert.equal('undefined', typeof res)
+          done()
+      });
+    })
+
   })
 
 })