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%%=============================================================================
%% Copyright 2011 Adam Lindberg & Erlang Solutions Ltd.
%%
%% Licensed under the Apache License, Version 2.0 (the "License");
%% you may not use this file except in compliance with the License.
%% You may obtain a copy of the License at
%%
%% http://www.apache.org/licenses/LICENSE-2.0
%%
%% Unless required by applicable law or agreed to in writing, software
%% distributed under the License is distributed on an "AS IS" BASIS,
%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
%% See the License for the specific language governing permissions and
%% limitations under the License.
%%=============================================================================
%% @author Adam Lindberg <eproxus@gmail.com>
%% @copyright 2011, Adam Lindberg & Erlang Solutions Ltd
%% @doc Module mocking library for Erlang.
-module(meck).
-behaviour(gen_server).
%% Interface exports
-export([new/1]).
-export([new/2]).
-export([expect/3]).
-export([expect/4]).
-export([sequence/4]).
-export([loop/4]).
-export([delete/3]).
-export([exception/2]).
-export([passthrough/1]).
-export([history/1]).
-export([history/2]).
-export([validate/1]).
-export([unload/0]).
-export([unload/1]).
-export([called/3]).
-export([called/4]).
-export([num_calls/3]).
-export([num_calls/4]).
-export([reset/1]).
%% Syntactic sugar
-export([loop/1]).
-export([seq/1]).
-export([val/1]).
-export([raise/2]).
%% Callback exports
-export([init/1]).
-export([handle_call/3]).
-export([handle_cast/2]).
-export([handle_info/2]).
-export([terminate/2]).
-export([code_change/3]).
-export([exec/5]).
%% Types
%% @type meck_mfa() = {Mod::atom(), Func::atom(), Args::list(term())}.
%% Module, function and arguments that the mock module got called with.
-type meck_mfa() :: {Mod::atom(), Func::atom(), Args::[term()]}.
%% @type history() = [{pid(), meck_mfa(), Result::term()}
%% | {pid(), meck_mfa(), Class:: exit | error | throw,
%% Reason::term(), Stacktrace::list(mfa())}].
%% History is a list of either successful function calls with a returned
%% result or function calls that resulted in an exception with a type,
%% reason and a stack trace. Each tuple begins with the pid of the process
%% that made the call to the function.
-type history() :: [{pid(), meck_mfa(), Result::term()}
| {pid(), meck_mfa(), Class:: exit | error | throw,
Reason::term(), Stacktrace::[mfa()]}].
%% @type args_pattern() = [term() | '_'].
%% Used in {@link expect/3} and {@link expect/4} to define an expectation by
%% an argument pattern. Every list element corresponds to a function argument
%% at the respective position. '_' is a wildcard that matches any value. The
%% length of the list defines the arity of the function an expectation is
%% created for.
-type args_pattern() :: [term() | '_'].
%% @type ret_spec().
%% Opaque data structure that defines values to be returned by expectations.
%% Values of `ret_spec' are constructed by {@link seq/1}, {@link loop/1},
%% {@link val/1}, and {@link raise/2} functions. They are used to specify
%% return values in {@link expect/3} and {@link expect/4} functions, and also
%% as the parameter of the `stub_all' option of {@link new/2} function.
-opaque ret_spec() :: {meck_val, term()} |
{meck_seq, [term()]} |
{meck_loop, [term()], [term()]} |
{meck_func, fun()} |
{meck_raise, throw | error | exit, term()} |
term().
%% Records
-record(state, {mod :: atom(),
can_expect :: any | [{atom(), non_neg_integer()}],
expects :: dict(),
valid = true :: boolean(),
history = [] :: history() | undefined,
original :: term(),
was_sticky :: boolean()}).
%% Includes
-include("meck_abstract.hrl").
-define(MATCH_SPEC(L), {L, [], ['$_']}).
%%=============================================================================
%% Interface exports
%%=============================================================================
%% @spec new(Mod:: atom() | list(atom())) -> ok
%% @equiv new(Mod, [])
-spec new(Mod:: atom() | [atom()]) -> ok.
new(Mod) when is_atom(Mod) -> new(Mod, []);
new(Mod) when is_list(Mod) -> lists:foreach(fun new/1, Mod), ok.
%% @spec new(Mod:: atom() | list(atom()), Options::list(term())) -> ok
%% @doc Creates new mocked module(s).
%%
%% This replaces the current version (if any) of the modules in `Mod'
%% with an empty module.
%%
%% Since this library is intended to use from test code, this
%% function links a process for each mock to the calling process.
%%
%% The valid options are:
%% <dl>
%% <dt>`passthrough'</dt>
%% <dd>Retains the original functions, if not mocked by meck. If used along
%% with `stub_all' then `stub_all' is ignored.</dd>
%%
%% <dt>`no_link'</dt>
%% <dd>Does not link the meck process to the caller process (needed for using
%% meck in rpc calls).</dd>
%%
%% <dt>`unstick'</dt>
%% <dd>Unstick the module to be mocked (e.g. needed for using meck with
%% kernel and stdlib modules).</dd>
%%
%% <dt>`no_passthrough_cover'</dt>
%% <dd>If cover is enabled on the module to be mocked then meck will continue
%% to capture coverage on passthrough calls. This option allows you to
%% disable that feature if it causes problems.</dd>
%%
%% <dt>`{spawn_opt, list()}'</dt>
%% <dd>Specify Erlang process spawn options. Typically used to specify
%% non-default, garbage collection options.</dd>
%%
%% <dt>`no_history'</dt>
%% <dd>Do not store history of meck calls.</dd>
%%
%% <dt>`non_strict'</dt>
%% <dd>A mock created with this option will allow setting expectations on
%% functions that are not exported from the mocked module. With this
%% option on it is even possible to mock non existing modules.</dd>
%%
%% <dt>`{stub_all, '{@link ret_spec()}`}'</dt>
%% <dd>Stubs all functions exported from the mocked module. The stubs will
%% return whatever defined by {@link ret_spec()} regardless of arguments
%% passed in. It is possible to specify this option as just `stub_all'
%% then stubs will return atom `ok'. If used along with `passthrough'
%% then `stub_all' is ignored. </dd>
%% </dl>
-spec new(Mod:: atom() | [atom()], Options::[term()]) -> ok.
new(Mod, Options) when is_atom(Mod), is_list(Options) ->
case start(Mod, Options) of
{ok, _Pid} -> ok;
{error, Reason} -> erlang:error(Reason, [Mod, Options])
end;
new(Mod, Options) when is_list(Mod) ->
lists:foreach(fun(M) -> new(M, Options) end, Mod),
ok.
%% @doc Add expectation for a function `Func' to the mocked modules `Mod'.
%%
%% An expectation is either of the following:
%% <dl>
%% <dt>`StubFun'</dt><dd>a stub function that is executed whenever the function
%% `Func' is called. The arity of `StubFun' identifies for which particular
%% `Func' variant an expectation is created for;</dd>
%% <dt>`ClauseSpecs'</dt><dd>a list of `ArgsPattern'/`RetSpec' pairs. Whenever
%% the function `Func' is called the arguments are matched against the
%% `ArgsPattern' in the list. As soon as the first match is found then a value
%% defined by the corresponding `RetSpec' is returned.</dd>
%% </dl>
%%
%% It affects the validation status of the mocked module(s). If an
%% expectation is called with the wrong number of arguments or invalid
%% arguments the mock module(s) is invalidated. It is also invalidated if
%% an unexpected exception occurs.
-spec expect(Mod, Func, Expect) -> ok when
Mod :: atom() | [atom()],
Func :: atom(),
Expect :: StubFun | [ClauseSpec],
StubFun :: fun(),
ClauseSpec :: {args_pattern(), ret_spec()}.
expect(Mod, Func, StubFun)
when is_atom(Mod), is_atom(Func), is_function(StubFun) ->
{arity, Arity} = erlang:fun_info(StubFun, arity),
Clause = {arity_2_matcher(Arity), {meck_func, StubFun}},
check_expect_result(call(Mod, {expect, {Func, Arity}, [Clause]}));
expect(Mod, Func, ClauseSpecs)
when is_atom(Mod), is_atom(Func), is_list(ClauseSpecs) ->
{Arity, Clauses} = parse_clause_specs(ClauseSpecs),
check_expect_result(call(Mod, {expect, {Func, Arity}, Clauses}));
expect(Mod, Func, Expect) when is_list(Mod) ->
lists:foreach(fun(M) -> expect(M, Func, Expect) end, Mod),
ok.
%% @doc Adds an expectation with the supplied arity and return value.
%%
%% This creates an expectation which takes `Arity' number of functions
%% and always returns `Result'.
%%
%% @see expect/3.
-spec expect(Mod, Func, ArgsSpec, RetSpec) -> ok when
Mod :: atom() | [atom()],
Func :: atom(),
ArgsSpec :: Arity | args_pattern(),
Arity :: non_neg_integer(),
RetSpec :: ret_spec().
expect(Mod, Func, Arity, RetSpec)
when is_atom(Mod), is_atom(Func), is_integer(Arity), Arity >= 0 ->
Clause = {arity_2_matcher(Arity), RetSpec},
check_expect_result(call(Mod, {expect, {Func, Arity}, [Clause]}));
expect(Mod, Func, ArgsPattern, RetSpec)
when is_atom(Mod), is_atom(Func), is_list(ArgsPattern) ->
{Arity, Clause} = parse_clause_spec({ArgsPattern, RetSpec}),
check_expect_result(call(Mod, {expect, {Func, Arity}, [Clause]}));
expect(Mod, Func, ArgsSpec, RetSpec) when is_list(Mod) ->
lists:foreach(fun(M) -> expect(M, Func, ArgsSpec, RetSpec) end, Mod),
ok.
%% @spec sequence(Mod:: atom() | list(atom()), Func::atom(),
%% Arity::pos_integer(), Sequence::[term()]) -> ok
%% @doc Adds an expectation which returns a value from `Sequence'
%% until exhausted.
%%
%% This creates an expectation which takes `Arity' number of arguments
%% and returns one element from `Sequence' at a time. Thus, calls to
%% this expect will exhaust the list of return values in order until
%% the last value is reached. That value is then returned for all
%% subsequent calls.
%%
%% @deprecated Please use {@link expect/3} or {@link expect/4} along with
%% {@link ret_spec()} generated by {@link seq/1}.
-spec sequence(Mod:: atom() | [atom()], Func::atom(),
Arity::pos_integer(), Sequence::[term()]) -> ok.
sequence(Mod, Func, Arity, Sequence)
when is_atom(Mod), is_atom(Func), is_integer(Arity), Arity >= 0 ->
Clause = {arity_2_matcher(Arity), seq(Sequence)},
check_expect_result(call(Mod, {expect, {Func, Arity}, [Clause]}));
sequence(Mod, Func, Arity, Sequence) when is_list(Mod) ->
lists:foreach(fun(M) -> sequence(M, Func, Arity, Sequence) end, Mod),
ok.
%% @spec loop(Mod:: atom() | list(atom()), Func::atom(),
%% Arity::pos_integer(), Loop::[term()]) -> ok
%% @doc Adds an expectation which returns a value from `Loop'
%% infinitely.
%%
%% This creates an expectation which takes `Arity' number of arguments
%% and returns one element from `Loop' at a time. Thus, calls to this
%% expect will return one element at a time from the list and will
%% restart at the first element when the end is reached.
%%
%% @deprecated Please use {@link expect/3} or {@link expect/4} along with
%% {@link ret_spec()} generated by {@link loop/1}.
-spec loop(Mod:: atom() | [atom()], Func::atom(),
Arity::pos_integer(), Loop::[term()]) -> ok.
loop(Mod, Func, Arity, Loop)
when is_atom(Mod), is_atom(Func), is_integer(Arity), Arity >= 0 ->
Clause = {arity_2_matcher(Arity), loop(Loop)},
check_expect_result(call(Mod, {expect, {Func, Arity}, [Clause]}));
loop(Mod, Func, Arity, Loop) when is_list(Mod) ->
lists:foreach(fun(M) -> loop(M, Func, Arity, Loop) end, Mod),
ok.
%% @spec delete(Mod:: atom() | list(atom()), Func::atom(),
%% Arity::pos_integer()) -> ok
%% @doc Deletes an expectation.
%%
%% Deletes the expectation for the function `Func' with the matching
%% arity `Arity'.
-spec delete(Mod:: atom() | [atom()], Func::atom(), Arity::pos_integer()) ->
ok.
delete(Mod, Func, Arity)
when is_atom(Mod), is_atom(Func), Arity >= 0 ->
call(Mod, {delete, Func, Arity});
delete(Mod, Func, Arity) when is_list(Mod) ->
lists:foreach(fun(M) -> delete(M, Func, Arity) end, Mod),
ok.
%% @spec exception(Class:: throw | error | exit, Reason::term()) -> no_return()
%% @doc Throws an expected exception inside an expect fun.
%%
%% This exception will get thrown without invalidating the mocked
%% module. That is, the code using the mocked module is expected to
%% handle this exception.
%%
%% <em>Note: this code should only be used inside an expect fun.</em>
-spec exception(Class:: throw | error | exit, Reason::term()) -> no_return().
exception(Class, Reason) when Class == throw; Class == error; Class == exit ->
throw(mock_exception_fun(Class, Reason)).
%% @spec passthrough(Args::list(term())) -> term()
%% @doc Calls the original function (if existing) inside an expectation fun.
%%
%% <em>Note: this code should only be used inside an expect fun.</em>
-spec passthrough(Args::[term()]) -> term().
passthrough(Args) when is_list(Args) ->
{Mod, Func} = get('$meck_call'),
erlang:apply(original_name(Mod), Func, Args).
%% @spec validate(Mod:: atom() | list(atom())) -> boolean()
%% @doc Validate the state of the mock module(s).
%%
%% The function returns `true' if the mocked module(s) has been used
%% according to its expectations. It returns `false' if a call has
%% failed in some way. Reasons for failure are wrong number of
%% arguments or non-existing function (undef), wrong arguments
%% (function clause) or unexpected exceptions.
%%
%% Use the {@link history/1} or {@link history/2} function to analyze errors.
-spec validate(Mod:: atom() | [atom()]) -> boolean().
validate(Mod) when is_atom(Mod) ->
call(Mod, validate);
validate(Mod) when is_list(Mod) ->
not lists:member(false, [validate(M) || M <- Mod]).
%% @spec history(Mod::atom()) -> history()
%% @doc Return the call history of the mocked module for all processes.
%%
%% @equiv history(Mod, '_')
-spec history(Mod::atom()) -> history().
history(Mod) when is_atom(Mod) -> call(Mod, history).
%% @spec history(Mod::atom(), Pid::pid()) -> history()
%% @doc Return the call history of the mocked module for the specified process.
%%
%% Returns a list of calls to the mocked module and their results for
%% the specified `Pid'. Results can be either normal Erlang terms or
%% exceptions that occurred.
%%
%% @see history/1
%% @see called/3
%% @see called/4
%% @see num_calls/3
%% @see num_calls/4
-spec history(Mod::atom(), Pid:: pid() | '_') -> history().
history(Mod, Pid) when is_atom(Mod), is_pid(Pid) orelse Pid == '_' ->
match_history(match_mfa('_', Pid), call(Mod, history)).
%% @spec unload() -> list(atom())
%% @doc Unloads all mocked modules from memory.
%%
%% The function returns the list of mocked modules that were unloaded
%% in the process.
-spec unload() -> [atom()].
unload() -> lists:foldl(fun unload_if_mocked/2, [], registered()).
%% @spec unload(Mod:: atom() | list(atom())) -> ok
%% @doc Unload a mocked module or a list of mocked modules.
%%
%% This will purge and delete the module(s) from the Erlang virtual
%% machine. If the mocked module(s) replaced an existing module, this
%% module will still be in the Erlang load path and can be loaded
%% manually or when called.
-spec unload(Mods:: atom() | [atom()]) -> ok.
unload(Mod) when is_atom(Mod) -> call(Mod, stop), wait_for_exit(Mod);
unload(Mods) when is_list(Mods) -> lists:foreach(fun unload/1, Mods), ok.
%% @spec called(Mod:: atom(), Fun:: atom(), Args:: list(term())) -> boolean()
%% @doc Returns whether `Mod:Func' has been called with `Args'.
%%
%% @equiv called(Mod, Fun, Args, '_')
called(Mod, Fun, Args) ->
has_call({Mod, Fun, Args}, meck:history(Mod)).
%% @spec called(Mod:: atom(), Fun:: atom(), Args:: list(term()),
%% Pid::pid()) -> boolean()
%% @doc Returns whether `Pid' has called `Mod:Func' with `Args'.
%%
%% This will check the history for the module, `Mod', to determine
%% whether process `Pid' call the function, `Fun', with arguments, `Args'. If
%% so, this function returns true, otherwise false.
%%
%% Wildcards can be used, at any level in any term, by using the underscore
%% atom: ``'_' ''
%%
%% @see called/3
-spec called(Mod::atom(), Fun::atom(), Args::list(), Pid::pid()) -> boolean().
called(Mod, Fun, Args, Pid) ->
has_call({Mod, Fun, Args}, meck:history(Mod, Pid)).
%% @spec num_calls(Mod:: atom(), Fun:: atom(), Args:: list(term()))
%% -> non_neg_integer()
%% @doc Returns the number of times `Mod:Func' has been called with `Args'.
%%
%% @equiv num_calls(Mod, Fun, Args, '_')
num_calls(Mod, Fun, Args) ->
num_calls({Mod, Fun, Args}, meck:history(Mod)).
%% @spec num_calls(Mod:: atom(), Fun:: atom(), Args:: list(term()),
%% Pid::pid()) -> non_neg_integer()
%% @doc Returns the number of times process `Pid' has called `Mod:Func'
%% with `Args'.
%%
%% This will check the history for the module, `Mod', to determine how
%% many times process `Pid' has called the function, `Fun', with
%% arguments, `Args' and returns the result.
%%
%% @see num_calls/3
-spec num_calls(Mod::atom(), Fun::atom(), Args::list(), Pid::pid()) ->
non_neg_integer().
num_calls(Mod, Fun, Args, Pid) ->
num_calls({Mod, Fun, Args}, meck:history(Mod, Pid)).
%% @doc Erases the call history for a mocked module or a list of mocked modules.
%%
%% This function will erase all calls made heretofore from the history of the
%% specified modules. It is intended to prevent cluttering of test results with
%% calls to mocked modules made during the test setup phase.
-spec reset(Mod::atom() | [atom()]) -> ok.
reset(Mod) when is_atom(Mod) ->
call(Mod, reset);
reset(Mods) when is_list(Mods) ->
lists:foreach(fun(Mod) -> reset(Mod) end, Mods).
%% @doc Converts a list of terms into {@link ret_spec()} defining a loop of
%% values. It is intended to be in construction of clause specs for the
%% {@link expect/3} function.
%%
%% Calls to an expect, created with {@link ret_spec()} returned by this function,
%% will return one element at a time from the `Loop' list and will restart at
%% the first element when the end is reached.
-spec loop(Loop::[term()]) -> ret_spec().
loop(L) when is_list(L) -> {meck_loop, L, L}.
%% @doc Converts a list of terms into {@link ret_spec()} defining a sequence of
%% values. It is intended to be in construction of clause specs for the
%% {@link expect/3} function.
%%
%% Calls to an expect, created with {@link ret_spec} returned by this function,
%% will exhaust the `Sequence' list of return values in order until the last
%% value is reached. That value is then returned for all subsequent calls.
-spec seq(Sequence::[term()]) -> ret_spec().
seq(S) when is_list(S) -> {meck_seq, S}.
%% @doc Converts a term into {@link ret_spec()} defining an individual value.
%% It is intended to be in construction of clause specs for the
%% {@link expect/3} function.
-spec val(Value::term()) -> ret_spec().
val(Value) -> {meck_value, Value}.
%% @doc Creates a {@link ret_spec()} that defines an exception.
%%
%% Calls to an expect, created with {@link ret_spec} returned by this function,
%% will raise the specified exception.
-spec raise(Class::throw|error|exit, Reason::term) -> ret_spec().
raise(throw, Reason) -> {meck_raise, throw, Reason};
raise(error, Reason) -> {meck_raise, error, Reason};
raise(exit, Reason) -> {meck_raise, exit, Reason}.
%%=============================================================================
%% Callback functions
%%=============================================================================
%% @hidden
init([Mod, Options]) ->
Exports = normal_exports(Mod),
WasSticky = case proplists:get_bool(unstick, Options) of
true -> {module, Mod} = code:ensure_loaded(Mod),
unstick_original(Mod);
_ -> false
end,
NoPassCover = proplists:get_bool(no_passthrough_cover, Options),
Original = backup_original(Mod, NoPassCover),
NoHistory = proplists:get_bool(no_history, Options),
History = if NoHistory -> undefined; true -> [] end,
CanExpect = resolve_can_expect(Exports, Options),
Expects = init_expects(Exports, Options),
process_flag(trap_exit, true),
try
_Bin = meck_mod:compile_and_load_forms(to_forms(Mod, Expects)),
{ok, #state{mod = Mod,
can_expect = CanExpect,
expects = Expects,
original = Original,
was_sticky = WasSticky,
history = History}}
catch
exit:{error_loading_module, Mod, sticky_directory} ->
{stop, module_is_sticky}
end.
%% @hidden
handle_call({get_expect, FuncAri, Args}, _From, S) ->
{Expect, NewExpects} = get_expect(S#state.expects, S#state.mod, FuncAri,
Args),
{reply, Expect, S#state{expects = NewExpects}};
handle_call({expect, FuncAri = {Func, Ari}, Clauses}, _From,
S = #state{mod = Mod, expects = Expects}) ->
case validate_expect(Mod, Func, Ari, S#state.can_expect) of
ok ->
NewExpects = store_expect(Mod, FuncAri, Clauses, Expects),
{reply, ok, S#state{expects = NewExpects}};
{error, Reason} ->
{reply, {error, Reason}, S}
end;
handle_call({delete, Func, Arity}, _From, S) ->
NewExpects = delete_expect(S#state.mod, {Func, Arity}, S#state.expects),
{reply, ok, S#state{expects = NewExpects}};
handle_call(history, _From, S = #state{history = undefined}) ->
{reply, [], S};
handle_call(history, _From, S) ->
{reply, lists:reverse(S#state.history), S};
handle_call(reset, _From, S) ->
{reply, ok, S#state{history = []}};
handle_call(invalidate, _From, S) ->
{reply, ok, S#state{valid = false}};
handle_call(validate, _From, S) ->
{reply, S#state.valid, S};
handle_call(stop, _From, S) ->
{stop, normal, ok, S}.
%% @hidden
handle_cast({add_history, _Item}, S = #state{history = undefined}) ->
{noreply, S};
handle_cast({add_history, Item}, S) ->
{noreply, S#state{history = [Item| S#state.history]}};
handle_cast(_Msg, S) ->
{noreply, S}.
%% @hidden
handle_info(_Info, S) -> {noreply, S}.
%% @hidden
terminate(_Reason, #state{mod = Mod, original = OriginalState,
was_sticky = WasSticky}) ->
export_original_cover(Mod, OriginalState),
cleanup(Mod),
restore_original(Mod, OriginalState, WasSticky),
ok.
%% @hidden
code_change(_OldVsn, S, _Extra) -> {ok, S}.
%% @hidden
exec(Pid, Mod, Func, Arity, Args) ->
Expect = call(Mod, {get_expect, {Func, Arity}, Args}),
try
put('$meck_call', {Mod, Func}),
Result = call_expect(Mod, Func, Expect, Args),
add_history(Pid, Mod, Func, Args, Result),
Result
catch
throw:Fun when is_function(Fun) ->
case is_mock_exception(Fun) of
true -> handle_mock_exception(Pid, Mod, Func, Fun, Args);
false -> invalidate_and_raise(Pid, Mod, Func, Args, throw, Fun)
end;
Class:Reason ->
invalidate_and_raise(Pid, Mod, Func, Args, Class, Reason)
after
erase('$meck_call')
end.
%%=============================================================================
%% Internal functions
%%=============================================================================
%% --- Process functions ------------------------------------------------------
start(Mod, Options) ->
case proplists:is_defined(no_link, Options) of
true -> start(start, Mod, Options);
false -> start(start_link, Mod, Options)
end.
start(Func, Mod, Options) ->
SpawnOpt = proplists:get_value(spawn_opt, Options, []),
gen_server:Func({local, proc_name(Mod)}, ?MODULE, [Mod, Options],
[{spawn_opt, SpawnOpt}]).
cast(Mod, Msg) -> gen_server(cast, Mod, Msg).
call(Mod, Msg) -> gen_server(call, Mod, Msg).
gen_server(Func, Mod, Msg) ->
Name = proc_name(Mod),
try gen_server:Func(Name, Msg)
catch exit:_Reason -> erlang:error({not_mocked, Mod}) end.
proc_name(Name) -> list_to_atom(atom_to_list(Name) ++ "_meck").
original_name(Name) -> list_to_atom(atom_to_list(Name) ++ "_meck_original").
wait_for_exit(Mod) ->
MonitorRef = erlang:monitor(process, proc_name(Mod)),
receive {'DOWN', MonitorRef, _Type, _Object, _Info} -> ok end.
unload_if_mocked(P, L) when is_atom(P) ->
unload_if_mocked(atom_to_list(P), L);
unload_if_mocked(P, L) when length(P) > 5 ->
case lists:split(length(P) - 5, P) of
{Name, "_meck"} ->
Mocked = list_to_existing_atom(Name),
try
unload(Mocked)
catch error:{not_mocked, Mocked} ->
ok
end,
[Mocked|L];
_Else ->
L
end;
unload_if_mocked(_P, L) ->
L.
%% --- Mock handling ----------------------------------------------------------
check_expect_result(ok) -> ok;
check_expect_result({error, Reason}) -> erlang:error(Reason).
validate_expect(M, F, A, CanExpect) ->
case expect_type(M, F, A) of
autogenerated ->
{error, {cannot_mock_autogenerated, {M, F, A}}};
builtin ->
{error, {cannot_mock_builtin, {M, F, A}}};
normal ->
case CanExpect =:= any orelse lists:member({F, A}, CanExpect) of
true -> ok;
_ -> {error, {undefined_function, {M, F, A}}}
end
end.
resolve_can_expect(Exports, Options) ->
NonStrict = proplists:get_bool(non_strict, Options),
case {Exports, NonStrict} of
{_, true} -> any;
{undefined, _} -> erlang:exit(undefined_module);
_ -> Exports
end.
init_expects(Exports, Options) ->
Passthrough = proplists:get_bool(passthrough, Options),
StubAll = proplists:is_defined(stub_all, Options),
Expects = case Exports of
undefined ->
[];
Exports when Passthrough ->
[passthrough_stub(FuncArity) || FuncArity <- Exports];
Exports when StubAll ->
StubRet = case lists:keyfind(stub_all, 1, Options) of
{stub_all, RetSpec} -> RetSpec;
_ -> val(ok)
end,
[void_stub(FuncArity, StubRet) || FuncArity <- Exports];
Exports ->
[]
end,
dict:from_list(Expects).
passthrough_stub({Func, Arity}) ->
{{Func, Arity}, [{arity_2_matcher(Arity), passthrough}]}.
void_stub({Func, Arity}, RetSpec) ->
{{Func, Arity}, [{arity_2_matcher(Arity), RetSpec}]}.
parse_clause_specs(ClauseSpecs) ->
parse_clause_specs(ClauseSpecs, undefined, []).
parse_clause_specs([ClauseSpec | Rest], undefined, []) ->
{Arity, Clause} = parse_clause_spec(ClauseSpec),
parse_clause_specs(Rest, Arity, [Clause]);
parse_clause_specs([ClauseSpec | Rest], DeducedArity, Clauses) ->
{Arity, Clause} = parse_clause_spec(ClauseSpec),
case Arity of
DeducedArity ->
parse_clause_specs(Rest, DeducedArity, [Clause | Clauses]);
_ ->
erlang:error({invalid_arity, {{expected, DeducedArity},
{actual, Arity},
{clause, Clause}}})
end;
parse_clause_specs([], DeducedArity, Clauses) ->
{DeducedArity, lists:reverse(Clauses)}.
parse_clause_spec({ArgsPattern, RetSpec}) ->
Arity = length(ArgsPattern),
MatchSpec = ets:match_spec_compile([?MATCH_SPEC(ArgsPattern)]),
Clause = {{pattern, ArgsPattern, MatchSpec}, RetSpec},
{Arity, Clause}.
get_expect(Expects, _Mod, FuncAri, Args) ->
case find_match(Args, dict:fetch(FuncAri, Expects)) of
not_found ->
{meck_undefined, Expects};
{ArgsMatcher, RetSpec} ->
case next_result(RetSpec, []) of
{Result, unchanged} ->
{Result, Expects};
{Result, NewRetSpec} ->
NewExpects = update_clause(Expects, FuncAri, ArgsMatcher,
NewRetSpec),
{Result, NewExpects}
end
end.
next_result(RetSpec = {meck_seq, [InnerRs | _Rest]}, Stack) ->
next_result(InnerRs, [RetSpec | Stack]);
next_result(RetSpec = {meck_loop, [InnerRs | _Rest], _Loop}, Stack) ->
next_result(InnerRs, [RetSpec | Stack]);
next_result(LeafRetSpec, Stack) ->
{LeafRetSpec, unwind_stack(LeafRetSpec, Stack, false)}.
unwind_stack(InnerRs, [], true) ->
InnerRs;
unwind_stack(_InnerRs, [], false) ->
unchanged;
unwind_stack(InnerRs, [CurrRs = {meck_seq, [InnerRs]} | Stack], Updated) ->
unwind_stack(CurrRs, Stack, Updated);
unwind_stack(InnerRs, [{meck_seq, [InnerRs | Rest]} | Stack], _Updated) ->
unwind_stack({meck_seq, Rest}, Stack, true);
unwind_stack(NewInnerRs, [{meck_seq, [_InnerRs | Rest]} | Stack], _Updated) ->
unwind_stack({meck_seq, [NewInnerRs | Rest]}, Stack, true);
unwind_stack(InnerRs, [{meck_loop, [InnerRs], Loop} | Stack], _Updated) ->
unwind_stack({meck_loop, Loop, Loop}, Stack, true);
unwind_stack(InnerRs, [{meck_loop, [InnerRs | Rest], Loop} | Stack],
_Updated) ->
unwind_stack({meck_loop, Rest, Loop}, Stack, true);
unwind_stack(NewInnerRs, [{meck_loop, [_InnerRs | Rest], Loop} | Stack],
_Updated) ->
unwind_stack({meck_loop, [NewInnerRs | Rest], Loop}, Stack, true).
store_expect(Mod, FuncAri, Clauses, Expects) ->
NewExpects = dict:store(FuncAri, Clauses, Expects),
_Bin = meck_mod:compile_and_load_forms(to_forms(Mod, NewExpects)),
NewExpects.
delete_expect(Mod, FuncAri, Expects) ->
NewExpects = dict:erase(FuncAri, Expects),
_Bin = meck_mod:compile_and_load_forms(to_forms(Mod, NewExpects)),
NewExpects.
update_clause(Expects, FuncAri, ArgsMatcher, RetSpec) ->
dict:update(FuncAri,
fun(Clauses) ->
lists:keyreplace(ArgsMatcher, 1, Clauses,
{ArgsMatcher, RetSpec})
end,
Expects).
find_match(Args, [{ArgsMatcher, RetSpec} | Rest]) ->
case ArgsMatcher of
{pattern, _ArgsPattern, MatchSpec} ->
case ets:match_spec_run([Args], MatchSpec) of
[] ->
find_match(Args, Rest);
_ ->
{ArgsMatcher, RetSpec}
end;
{hamcrest, _Matchers} ->
throw(unimplemented) % TODO Hamcrest support is comming
end;
find_match(_Args, []) ->
not_found.
arity_2_matcher(Arity) ->
ArgsPattern = lists:duplicate(Arity, '_'),
MatchSpec = ets:match_spec_compile([?MATCH_SPEC(ArgsPattern)]),
{pattern, ArgsPattern, MatchSpec}.
%% --- Code generation --------------------------------------------------------
func(Mod, {Func, Arity}, {anon, Arity, Result}) ->
case contains_opaque(Result) of
true ->
func_exec(Mod, Func, Arity);
false ->
func_native(Mod, Func, Arity, Result)
end;
func(Mod, {Func, Arity}, _Expect) ->
func_exec(Mod, Func, Arity).
func_exec(Mod, Func, Arity) ->
Args = args(Arity),
?function(Func, Arity,
[?clause(Args,
[?call(?MODULE, exec,
[?call(erlang, self, []),
?atom(Mod),
?atom(Func),
?integer(Arity),
list(Args)])])]).
func_native(Mod, Func, Arity, Result) ->
Args = args(Arity),
AbsResult = erl_parse:abstract(Result),
?function(
Func, Arity,
[?clause(
Args,
[?call(gen_server, cast,
[?atom(proc_name(Mod)),
?tuple([?atom(add_history),
?tuple([?call(erlang, self, []),
?tuple([?atom(Mod), ?atom(Func),
list(Args)]),
AbsResult])])]),
AbsResult])]).
contains_opaque(Term) when is_pid(Term); is_port(Term); is_function(Term);
is_reference(Term) ->
true;
contains_opaque(Term) when is_list(Term) ->
lists:any(fun contains_opaque/1, Term);
contains_opaque(Term) when is_tuple(Term) ->
lists:any(fun contains_opaque/1, tuple_to_list(Term));
contains_opaque(_Term) ->
false.
to_forms(Mod, Expects) ->
{Exports, Functions} = functions(Mod, Expects),
[?attribute(module, Mod)] ++ attributes(Mod) ++ Exports ++ Functions.
attributes(Mod) ->
try
[?attribute(Key, Val) || {Key, Val} <-
proplists:get_value(attributes, Mod:module_info(), []),
Key =/= vsn]
catch
error:undef -> []
end.
functions(Mod, Expects) ->
dict:fold(fun(Export, Expect, {Exports, Functions}) ->
{[?attribute(export, [Export])|Exports],
[func(Mod, Export, Expect)|Functions]}
end, {[], []}, Expects).
args(0) -> [];
args(Arity) -> [?var(var_name(N)) || N <- lists:seq(1, Arity)].
list([]) -> {nil, ?LINE};
list([H|T]) -> {cons, ?LINE, H, list(T)}.
var_name(A) -> list_to_atom("A"++integer_to_list(A)).
%% --- Execution utilities ----------------------------------------------------
is_local_function(Fun) ->
{module, Module} = erlang:fun_info(Fun, module),
?MODULE == Module.
handle_mock_exception(Pid, Mod, Func, Fun, Args) ->
case Fun() of
{exception, Class, Reason} ->
% exception created with the mock:exception function,
% do not invalidate Mod
raise(Pid, Mod, Func, Args, Class, Reason)
end.
-spec invalidate_and_raise(_, _, _, _, _, _) -> no_return().
invalidate_and_raise(Pid, Mod, Func, Args, Class, Reason) ->
call(Mod, invalidate),
raise(Pid, Mod, Func, Args, Class, Reason).
raise(Pid, Mod, Func, Args, Class, Reason) ->
Stacktrace = inject(Mod, Func, Args, erlang:get_stacktrace()),
add_history(Pid, Mod, Func, Args, Class, Reason, Stacktrace),
erlang:raise(Class, Reason, Stacktrace).
mock_exception_fun(Class, Reason) -> fun() -> {exception, Class, Reason} end.
call_expect(_Mod, _Func, meck_undefined, _Args) ->
erlang:error(function_clause);
call_expect(_Mod, _Func, {meck_value, Value}, _Args) ->
Value;
call_expect(_Mod, _Func, {meck_func, Fun}, Args) when is_function(Fun) ->
apply(Fun, Args);
call_expect(_Mod, _Func, {meck_raise, Class, Reason}, _Args) ->
exception(Class, Reason);
call_expect(Mod, Func, passthrough, Args) ->
apply(original_name(Mod), Func, Args);
call_expect(_Mod, _Func, Value, _Args) ->
Value.
inject(_Mod, _Func, _Args, []) ->
[];
inject(Mod, Func, Args, [{meck, exec, _Arity} = Meck|Stack]) ->
[Meck, {Mod, Func, Args}|Stack];
inject(Mod, Func, Args, [{meck, exec, _Arity, _Location} = Meck|Stack]) ->
[Meck, {Mod, Func, Args}|Stack];
inject(Mod, Func, Args, [H|Stack]) ->
[H|inject(Mod, Func, Args, Stack)].
is_mock_exception(Fun) -> is_local_function(Fun).
%% --- Original module handling -----------------------------------------------
backup_original(Module, NoPassCover) ->
Cover = get_cover_state(Module),
try
Forms = meck_mod:abstract_code(meck_mod:beam_file(Module)),
NewName = original_name(Module),
CompileOpts = meck_mod:compile_options(meck_mod:beam_file(Module)),
Renamed = meck_mod:rename_module(Forms, NewName),
Binary = meck_mod:compile_and_load_forms(Renamed, CompileOpts),
%% At this point we care about `Binary' if and only if we want
%% to recompile it to enable cover on the original module code
%% so that we can still collect cover stats on functions that
%% have not been mocked. Below are the different values
%% passed back along with `Cover'.
%%
%% `no_passthrough_cover' - there is no coverage on the
%% original module OR passthrough coverage has been disabled
%% via the `no_passthrough_cover' option
%%
%% `no_binary' - something went wrong while trying to compile
%% the original module in `backup_original'
%%
%% Binary - a `binary()' of the compiled code for the original
%% module that is being mocked, this needs to be passed around
%% so that it can be passed to Cover later. There is no way
%% to use the code server to access this binary without first
%% saving it to disk. Instead, it's passed around as state.
if (Cover == false) orelse NoPassCover ->
Binary2 = no_passthrough_cover;
true ->
Binary2 = Binary,
meck_cover:compile_beam(NewName, Binary2)
end,
{Cover, Binary2}
catch
throw:{object_code_not_found, _Module} ->
{Cover, no_binary}; % TODO: What to do here?
throw:no_abstract_code ->
{Cover, no_binary} % TODO: What to do here?
end.
restore_original(Mod, {false, _}, WasSticky) ->
restick_original(Mod, WasSticky),
ok;
restore_original(Mod, OriginalState={{File, Data, Options},_}, WasSticky) ->
case filename:extension(File) of
".erl" ->
{ok, Mod} = cover:compile_module(File, Options);
".beam" ->
cover:compile_beam(File)
end,
restick_original(Mod, WasSticky),
import_original_cover(Mod, OriginalState),
ok = cover:import(Data),
ok = file:delete(Data),
ok.
%% @doc Import the cover data for `<name>_meck_original' but since it
%% was modified by `export_original_cover' it will count towards
%% `<name>'.
import_original_cover(Mod, {_,Bin}) when is_binary(Bin) ->
OriginalData = atom_to_list(original_name(Mod)) ++ ".coverdata",
ok = cover:import(OriginalData),
ok = file:delete(OriginalData);
import_original_cover(_, _) ->
ok.
%% @doc Export the cover data for `<name>_meck_original' and modify
%% the data so it can be imported under `<name>'.
export_original_cover(Mod, {_, Bin}) when is_binary(Bin) ->
OriginalMod = original_name(Mod),
File = atom_to_list(OriginalMod) ++ ".coverdata",
ok = cover:export(File, OriginalMod),
ok = meck_cover:rename_module(File, Mod);
export_original_cover(_, _) ->
ok.
unstick_original(Module) -> unstick_original(Module, code:is_sticky(Module)).
unstick_original(Module, true) -> code:unstick_mod(Module);
unstick_original(_,_) -> false.
restick_original(Module, true) ->
code:stick_mod(Module),
{module, Module} = code:ensure_loaded(Module),
ok;
restick_original(_,_) -> ok.
get_cover_state(Module) -> get_cover_state(Module, cover:is_compiled(Module)).
get_cover_state(Module, {file, File}) ->
Data = atom_to_list(Module) ++ ".coverdata",
ok = cover:export(Data, Module),
CompileOptions =
try
meck_mod:compile_options(meck_mod:beam_file(Module))
catch
throw:{object_code_not_found, _Module} -> []
end,
{File, Data, CompileOptions};
get_cover_state(_Module, _IsCompiled) ->
false.
normal_exports(M) ->
try
[FA || FA = {F, A} <- M:module_info(exports),
normal == expect_type(M, F, A)]
catch
error:undef -> undefined
end.
%% Functions we should not create expects for (auto-generated and BIFs)
expect_type(_, module_info, 0) -> autogenerated;
expect_type(_, module_info, 1) -> autogenerated;
expect_type(M, F, A) -> expect_type(erlang:is_builtin(M, F, A)).
expect_type(true) -> builtin;
expect_type(false) -> normal.
cleanup(Mod) ->
code:purge(Mod),
code:delete(Mod),
code:purge(original_name(Mod)),
code:delete(original_name(Mod)).
%% --- History utilities ------------------------------------------------------
add_history(Pid, Mod, Func, Args, Result) ->
add_history(Mod, {Pid, {Mod, Func, Args}, Result}).
add_history(Pid, Mod, Func, Args, Class, Reason, Stacktrace) ->
add_history(Mod, {Pid, {Mod, Func, Args}, Class, Reason, Stacktrace}).
add_history(Mod, Item) ->
cast(Mod, {add_history, Item}).
has_call(MFA, History) ->
[] =/= match_history(match_mfa(MFA), History).
num_calls(MFA, History) ->
length(match_history(match_mfa(MFA), History)).
match_history(MatchSpec, History) ->
MS = ets:match_spec_compile(MatchSpec),
ets:match_spec_run(History, MS).
match_mfa(MFA) -> match_mfa(MFA, '_').
match_mfa(MFA, Pid) ->
[?MATCH_SPEC({Pid, MFA, '_'}),
?MATCH_SPEC({Pid, MFA, '_', '_', '_'})].
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