Assert that a callback is always a function

Author: axic

test/package.js

@@ -177,6 +177,22 @@ tape('Compilation', function (t) {
     st.end();
   });
 
+  t.test('lazy-loading callback fails properly (with invalid callback)', function (st) {
+    if (semver.lt(solc.semver(), '0.2.1')) {
+      st.skip('Not supported by solc <0.2.1');
+      st.end();
+      return;
+    }
+
+    var input = {
+      'cont.sol': 'import "lib.sol"; contract x { function g() { L.f(); } }'
+    };
+    st.throws(function () {
+      solc.compile({sources: input}, 0, "this isn't a callback");
+    }, /Invalid callback specified./);
+    st.end();
+  });
+
   t.test('file import without lazy-loading callback fails properly', function (st) {
     if (semver.lt(solc.semver(), '0.2.1')) {
       st.skip('Not supported by solc <0.2.1');

wrapper.js

@@ -1,3 +1,4 @@
+var assert = require('assert');
 var translate = require('./translate.js');
 var linker = require('./linker.js');
 var requireFromString = require('require-from-string');
@@ -20,6 +21,7 @@ function setupMethods (soljson) {
       soljson.setValue(ptr, buffer, '*');
     };
     var wrapCallback = function (callback) {
+      assert(typeof callback === 'function', 'Invalid callback specified.');
       return function (path, contents, error) {
         var result = callback(soljson.Pointer_stringify(path));
         if (typeof result.contents === 'string') {