Allow errors to be raised when a mocked call occurs. Closes #3.

Author: ryanplusplus

spec/mach_spec.lua

@@ -81,6 +81,30 @@ describe('The mach library', function()
     end)
   end)
 
+  it('should allow you to specify errors to be raised when a mocked function is called', function()
+    local f = mach.mock_function('f')
+
+    f:should_be_called():
+      and_will_raise_error('some error message'):
+      when(function()
+        should_fail_with('some error message', function()
+          f()
+        end)
+      end)
+  end)
+
+  it('should allow calls to be completed after a call that raises an error', function()
+    local f = mach.mock_function('f')
+
+    f:should_be_called():
+      and_will_raise_error('some error message'):
+      and_then(f:should_be_called():and_will_return(4)):
+      when(function()
+        pcall(function() f() end)
+        assert.is.equal(f(), 4)
+      end)
+  end)
+
   it('should allow you to check that a function has been called multiple times', function()
     local f = mach.mock_function('f')
 

src/mach/Expectation.lua

@@ -27,6 +27,16 @@ function expectation:and_will_return(...)
   return self
 end
 
+function expectation:and_will_raise_error(...)
+  -- if not self._call_specified then
+  --   error('cannot set return value for an unspecified call', 2)
+  -- end
+
+  self._calls[#self._calls]:set_error(...)
+
+  return self
+end
+
 function expectation:when(thunk)
   if not self._call_specified then
     error('incomplete expectation', 2)
@@ -46,7 +56,13 @@ function expectation:when(thunk)
             self._calls[i - 1]:fix_order()
           end
 
-          return table.remove(self._calls, i):get_return_values()
+          table.remove(self._calls, i)
+
+          if call:has_error() then
+            error(call:get_error())
+          end
+
+          return call:get_return_values()
         end
       end
 

src/mach/ExpectedCall.lua

@@ -37,6 +37,18 @@ function expected_call:get_return_values(...)
   return table.unpack(self._return)
 end
 
+function expected_call:set_error(...)
+  self._error = table.pack(...)
+end
+
+function expected_call:get_error(...)
+  return table.unpack(self._error)
+end
+
+function expected_call:has_error()
+  return self._error ~= nil
+end
+
 function expected_call:fix_order()
   self._ordered = true
 end