const std = @import("std");
const StringHashMap = std.StringHashMap;
const expect = std.testing.expect;
const expectEqual = std.testing.expectEqual;
const GlobalAllocator = std.testing.allocator;
const TailQueue = std.TailQueue;
////Imports////
///
/// The enumeration of types that the mocking framework supports. These include basic types like u8
/// and function types like fn () void.
///
////DataElementType////
///
/// A tagged union of all the data elements that the mocking framework can work with. This can be
/// expanded to add new types. This is needed as need a list of data that all have different types,
/// so this wraps the data into a union, (which is of one type) so can have a list of them.
/// When https://github.com/ziglang/zig/issues/383 and https://github.com/ziglang/zig/issues/2907
/// is done, can programitaclly create types for this. Can use a compile time block that loops
/// through the available basic types and create function types so don't have a long list.
///
////DataElement////
///
/// The type of actions that the mocking framework can perform.
///
const ActionType = enum {
/// This will test the parameters passed to a function. It will test the correct types and
/// value of each parameter. This is also used to return a specific value from a function so
/// can test for returns from a function.
TestValue,
/// This action is to replace a function call to be mocked with another function the user
/// chooses to be replaced. This will consume the function call. This will allow the user to
/// check that the function is called once or multiple times by added a function to be mocked
/// multiple times. This also allows the ability for a function to be mocked by different
/// functions each time it is called.
ConsumeFunctionCall,
/// This is similar to the ConsumeFunctionCall action, but will call the mocked function
/// repeatedly until the mocking is done.
RepeatFunctionCall,
// Other actions that could be used
// This will check that a function isn't called.
//NoFunctionCall
// This is a generalisation of ConsumeFunctionCall and RepeatFunctionCall but can specify how
// many times a function can be called.
//FunctionCallN
};
///
/// This is a pair of action and data to be actioned on.
///
const Action = struct {
action: ActionType,
data: DataElement,
};
///
/// The type for a queue of actions using std.TailQueue.
///
const ActionList = TailQueue(Action);
///
/// The type for linking the function name to be mocked and the action list to be acted on.
///
const NamedActionMap = StringHashMap(ActionList);
///
/// The mocking framework.
///
/// Return: type
/// This returns a struct for adding and acting on mocked functions.
///
fn Mock() type {
return struct {
const Self = @This();
/// The map of function name and action list.
named_actions: NamedActionMap,
///
/// Create a DataElement from data. This wraps data into a union. This allows the ability
/// to have a list of different types.
///
/// Arguments:
/// IN arg: anytype - The data, this can be a function or basic type value.
///
/// Return: DataElement
/// A DataElement with the data wrapped.
///
fn createDataElement(arg: anytype) DataElement {
return switch (@TypeOf(arg)) {
////createDataElement////
};
}
///
/// Get the enum that represents the type given.
///
/// Arguments:
/// IN comptime T: type - A type.
///
/// Return: DataElementType
/// The DataElementType that represents the type given.
///
fn getDataElementType(comptime T: type) DataElementType {
return switch (T) {
////getDataElementType////
};
}
///
/// Get the data out of the tagged union
///
/// Arguments:
/// IN comptime T: type - The type of the data to extract. Used to switch on the
/// tagged union.
/// IN element: DataElement - The data element to unwrap the data from.
///
/// Return: T
/// The data of type T from the DataElement.
///
fn getDataValue(comptime T: type, element: DataElement) T {
return switch (T) {
////getDataValue////
};
}
///
/// Create a function type from a return type and its arguments.
///
/// Arguments:
/// IN comptime RetType: type - The return type of the function.
/// IN params: type - The parameters of the function. This will be the type
/// of a anonymous struct to get the fields and types.
///
/// Return: type
/// A function type that represents the return type and its arguments.
///
fn getFunctionType(comptime RetType: type, params: type) type {
const fields = @typeInfo(params).Struct.fields;
return switch (fields.len) {
0 => fn () RetType,
1 => fn (fields[0].field_type) RetType,
2 => fn (fields[0].field_type, fields[1].field_type) RetType,
3 => fn (fields[0].field_type, fields[1].field_type, fields[2].field_type) RetType,
4 => fn (fields[0].field_type, fields[1].field_type, fields[2].field_type, fields[3].field_type) RetType,
else => @compileError("More than 3 parameters not supported"),
};
}
///
/// Call a function with the function definitions and parameters.
///
/// Argument:
/// IN comptime RetType: type - The return type of the function.
/// IN function_type: anytype - The function pointer to call.
/// IN params: anytype - The parameter(s) of the function.
///
/// Return: RetType
/// The return value of the called function. This can be void.
///
fn callFunction(comptime RetType: type, function_type: anytype, params: anytype) RetType {
return switch (params.len) {
0 => function_type(),
1 => function_type(params[0]),
2 => function_type(params[0], params[1]),
3 => function_type(params[0], params[1], params[2]),
4 => function_type(params[0], params[1], params[2], params[3]),
// Should get to this as `getFunctionType` will catch this
else => @compileError("More than 3 parameters not supported"),
};
}
///
/// Perform a generic function action. This can be part of a ConsumeFunctionCall or
/// RepeatFunctionCall action. This will perform the function type comparison and
/// call the function stored in the action list.
///
/// Argument:
/// IN comptime RetType: type - The return type of the function to call.
/// IN test_element: DataElement - The test value to compare to the generated function
/// type. This is also the function that will be called.
/// IN params: anytype - The parameters of the function to call.
///
/// Return: RetType
/// The return value of the called function. This can be void.
///
fn performGenericFunction(comptime RetType: type, test_element: DataElement, params: anytype) RetType {
// Get the expected function type
const expected_function = getFunctionType(RetType, @TypeOf(params));
// Test that the types match
const expect_type = comptime getDataElementType(expected_function);
expectEqual(expect_type, @as(DataElementType, test_element));
// Types match, so can use the expected type to get the actual data
const actual_function = getDataValue(expected_function, test_element);
return callFunction(RetType, actual_function, params);
}
///
/// This tests a value passed to a function.
///
/// Arguments:
/// IN comptime ExpectedType: type - The expected type of the value to be tested.
/// IN expected_value: ExpectedType - The expected value to be tested. This is what was
/// passed to the functions.
/// IN elem: DataElement - The wrapped data element to test against the
/// expected value.
///
fn expectTest(comptime ExpectedType: type, expected_value: ExpectedType, elem: DataElement) void {
if (ExpectedType == void) {
// Can't test void as it has no value
std.debug.panic("Can not test a value for void\n", .{});
}
// Test that the types match
const expect_type = comptime getDataElementType(ExpectedType);
expectEqual(expect_type, @as(DataElementType, elem));
// Types match, so can use the expected type to get the actual data
const actual_value = getDataValue(ExpectedType, elem);
// Test the values
expectEqual(expected_value, actual_value);
}
///
/// This returns a value from the wrapped data element. This will be a test value to be
/// returned by a mocked function.
///
/// Arguments:
/// IN comptime fun_name: []const u8 - The function name to be used to tell the user if
/// there is no return value set up.
/// IN/OUT action_list: *ActionList - The action list to extract the return value from.
/// IN comptime DataType: type - The type of the return value.
///
/// Return: RetType
/// The return value of the expected value.
///
fn expectGetValue(comptime fun_name: []const u8, action_list: *ActionList, comptime DataType: type) DataType {
if (DataType == void) {
return;
}
if (action_list.*.popFirst()) |action_node| {
// Free the node
defer GlobalAllocator.destroy(action_node);
const action = action_node.data;
// Test that the data match
const expect_data = comptime getDataElementType(DataType);
expectEqual(expect_data, @as(DataElementType, action.data));
return getDataValue(DataType, action.data);
} else {
std.debug.panic("No more test values for the return of function: " ++ fun_name ++ "\n", .{});
}
}
///
/// This adds a action to the action list with ActionType provided. It will create a new
/// mapping if one doesn't exist for a function name.
///
/// Arguments:
/// IN/OUT self: *Self - Self. This is the mocking object to be modified
/// to add the test data.
/// IN comptime fun_name: []const u8 - The function name to add the test data to.
/// IN data: anytype - The data to add to the action for the function.
/// IN action_type: ActionType - The action type to add.
///
pub fn addAction(self: *Self, comptime fun_name: []const u8, data: anytype, action_type: ActionType) void {
// Add a new mapping if one doesn't exist.
if (!self.named_actions.contains(fun_name)) {
self.named_actions.put(fun_name, .{}) catch unreachable;
}
// Get the function mapping to add the parameter to.
if (self.named_actions.getEntry(fun_name)) |actions_kv| {
// Take a reference of the value so the underlying action list will update
var action_list = &actions_kv.value;
const action = Action{
.action = action_type,
.data = createDataElement(data),
};
var a = GlobalAllocator.create(TailQueue(Action).Node) catch unreachable;
a.* = .{ .data = action };
action_list.*.append(a);
} else {
// Shouldn't get here as we would have just added a new mapping
// But just in case ;)
std.debug.panic("No function name: " ++ fun_name ++ "\n", .{});
}
}
///
/// Perform an action on a function. This can be one of ActionType.
///
/// Arguments:
/// IN/OUT self: *Self - Self. This is the mocking object to be modified
/// to perform a action.
/// IN comptime fun_name: []const u8 - The function name to act on.
/// IN comptime RetType: type - The return type of the function being mocked.
/// IN params: anytype - The list of parameters of the mocked function.
///
/// Return: RetType
/// The return value of the mocked function. This can be void.
///
pub fn performAction(self: *Self, comptime fun_name: []const u8, comptime RetType: type, params: anytype) RetType {
if (self.named_actions.getEntry(fun_name)) |kv_actions_list| {
// Take a reference of the value so the underlying action list will update
var action_list = &kv_actions_list.value;
// Peak the first action to test the action type
if (action_list.*.first) |action_node| {
const action = action_node.data;
return switch (action.action) {
ActionType.TestValue => ret: {
comptime var i = 0;
inline while (i < params.len) : (i += 1) {
// Now pop the action as we are going to use it
// Have already checked that it is not null
const test_node = action_list.*.popFirst().?;
defer GlobalAllocator.destroy(test_node);
const test_action = test_node.data;
const param = params[i];
const param_type = @TypeOf(params[i]);
expectTest(param_type, param, test_action.data);
}
break :ret expectGetValue(fun_name, action_list, RetType);
},
ActionType.ConsumeFunctionCall => ret: {
// Now pop the action as we are going to use it
// Have already checked that it is not null
const test_node = action_list.*.popFirst().?;
// Free the node once done
defer GlobalAllocator.destroy(test_node);
const test_element = test_node.data.data;
break :ret performGenericFunction(RetType, test_element, params);
},
ActionType.RepeatFunctionCall => ret: {
// Do the same for ActionType.ConsumeFunctionCall but instead of
// popping the function, just peak
const test_element = action.data;
break :ret performGenericFunction(RetType, test_element, params);
},
};
} else {
std.debug.panic("No action list elements for function: " ++ fun_name ++ "\n", .{});
}
} else {
std.debug.panic("No function name: " ++ fun_name ++ "\n", .{});
}
}
///
/// Initialise the mocking framework.
///
/// Return: Self
/// An initialised mocking framework.
///
pub fn init() Self {
return Self{
.named_actions = StringHashMap(ActionList).init(GlobalAllocator),
};
}
///
/// End the mocking session. This will check all test parameters and consume functions are
/// consumed. Any repeat functions are deinit.
///
/// Arguments:
/// IN/OUT self: *Self - Self. This is the mocking object to be modified to finished
/// the mocking session.
///
pub fn finish(self: *Self) void {
// Make sure the expected list is empty
var it = self.named_actions.iterator();
while (it.next()) |next| {
// Take a reference so the underlying action list will be updated.
var action_list = &next.value;
if (action_list.*.popFirst()) |action_node| {
const action = action_node.data;
switch (action.action) {
ActionType.TestValue, ActionType.ConsumeFunctionCall => {
// These need to be all consumed
std.debug.panic("Unused testing value: Type: {}, value: {} for function '{s}'\n", .{ action.action, @as(DataElementType, action.data), next.key });
},
ActionType.RepeatFunctionCall => {
// As this is a repeat action, the function will still be here
// So need to free it
GlobalAllocator.destroy(action_node);
},
}
}
}
// Free the function mapping
self.named_actions.deinit();
}
};
}
/// The global mocking object that is used for a mocking session. Maybe in the future, we can have
/// local mocking objects so can run the tests in parallel.
var mock: ?Mock() = null;
///
/// Get the mocking object and check we have one initialised.
///
/// Return: *Mock()
/// Pointer to the global mocking object so can be modified.
///
fn getMockObject() *Mock() {
// Make sure we have a mock object
if (mock) |*m| {
return m;
} else {
std.debug.panic("MOCK object doesn't exists, please initialise this test\n", .{});
}
}
///
/// Initialise the mocking framework.
///
pub fn initTest() void {
// Make sure there isn't a mock object
if (mock) |_| {
std.debug.panic("MOCK object already exists, please free previous test\n", .{});
} else {
mock = Mock().init();
}
}
///
/// End the mocking session. This will check all test parameters and consume functions are
/// consumed. Any repeat functions are deinit.
///
pub fn freeTest() void {
getMockObject().finish();
// This will stop double frees
mock = null;
}
///
/// Add a list of test parameters to the action list. This will create a list of data
/// elements that represent the list of parameters that will be passed to a mocked
/// function. A mocked function may be called multiple times, so this list may contain
/// multiple values for each call to the same mocked function.
///
/// Arguments:
/// IN comptime fun_name: []const u8 - The function name to add the test parameters to.
/// IN params: anytype - The parameters to add.
///
pub fn addTestParams(comptime fun_name: []const u8, params: anytype) void {
var mock_obj = getMockObject();
comptime var i = 0;
inline while (i < params.len) : (i += 1) {
mock_obj.addAction(fun_name, params[i], ActionType.TestValue);
}
}
///
/// Add a function to mock out another. This will add a consume function action, so once
/// the mocked function is called, this action wil be removed.
///
/// Arguments:
/// IN comptime fun_name: []const u8 - The function name to add the function to.
/// IN function: anytype - The function to add.
///
pub fn addConsumeFunction(comptime fun_name: []const u8, function: anytype) void {
getMockObject().addAction(fun_name, function, ActionType.ConsumeFunctionCall);
}
///
/// Add a function to mock out another. This will add a repeat function action, so once
/// the mocked function is called, this action wil be removed.
///
/// Arguments:
/// IN comptime fun_name: []const u8 - The function name to add the function to.
/// IN function: anytype - The function to add.
///
pub fn addRepeatFunction(comptime fun_name: []const u8, function: anytype) void {
getMockObject().addAction(fun_name, function, ActionType.RepeatFunctionCall);
}
///
/// Perform an action on a function. This can be one of ActionType.
///
/// Arguments:
/// IN comptime fun_name: []const u8 - The function name to act on.
/// IN comptime RetType: type - The return type of the function being mocked.
/// IN params: anytype - The list of parameters of the mocked function.
///
/// Return: RetType
/// The return value of the mocked function. This can be void.
///
pub fn performAction(comptime fun_name: []const u8, comptime RetType: type, params: anytype) RetType {
return getMockObject().performAction(fun_name, RetType, params);
}