From 50feeaa285b651c8661e25984af4ce58f88c9340 Mon Sep 17 00:00:00 2001
From: Jeroen van Rijn <Kelimion@users.noreply.github.com>
Date: Sat, 31 Jul 2021 23:47:52 +0200
Subject: [PATCH] big: Add test for `factorial`.

---
 core/math/big/build.bat |  4 ++--
 core/math/big/test.odin | 18 ++++++++++++++++++
 core/math/big/test.py   | 17 ++++++++++++++++-
 3 files changed, 36 insertions(+), 3 deletions(-)

diff --git a/core/math/big/build.bat b/core/math/big/build.bat
index 2a21e4f98..69dfe7995 100644
--- a/core/math/big/build.bat
+++ b/core/math/big/build.bat
@@ -1,7 +1,7 @@
 @echo off
-odin run   . -vet
+:odin run   . -vet
 :odin build . -build-mode:shared -show-timings -o:minimal -use-separate-modules
-:odin build . -build-mode:shared -show-timings -o:size -use-separate-modules
+odin build . -build-mode:shared -show-timings -o:size -use-separate-modules
 :odin build . -build-mode:shared -show-timings -o:speed -use-separate-modules
 
 python test.py
diff --git a/core/math/big/test.odin b/core/math/big/test.odin
index b8643813c..a03a7e879 100644
--- a/core/math/big/test.odin
+++ b/core/math/big/test.odin
@@ -276,3 +276,21 @@ PyRes :: struct {
 	return PyRes{res = r, err = .None};
 }
 
+/*
+	dest = factorial(n)
+*/
+@export test_factorial :: proc "c" (n: DIGIT) -> (res: PyRes) {
+	context = runtime.default_context();
+	err: Error;
+
+	dest := &Int{};
+	defer destroy(dest);
+
+	if err = factorial(dest, n); err != .None { return PyRes{res=":factorial:factorial(n):", err=err}; }
+
+	r: cstring;
+	r, err = int_itoa_cstring(dest, 16, context.temp_allocator);
+	if err != .None { return PyRes{res=":factorial:itoa(res):", err=err}; }
+	return PyRes{res = r, err = .None};
+}
+
diff --git a/core/math/big/test.py b/core/math/big/test.py
index abfa42336..75152821f 100644
--- a/core/math/big/test.py
+++ b/core/math/big/test.py
@@ -134,6 +134,8 @@ int_shl        = load(l.test_shl, [c_char_p, c_longlong], Res)
 int_shr        = load(l.test_shr, [c_char_p, c_longlong], Res)
 int_shr_signed = load(l.test_shr_signed, [c_char_p, c_longlong], Res)
 
+int_factorial  = load(l.test_factorial, [c_uint64], Res)
+
 def test(test_name: "", res: Res, param=[], expected_error = Error.Okay, expected_result = "", radix=16):
 	passed = True
 	r = None
@@ -321,6 +323,16 @@ def test_shr_signed(a = 0, bits = 0, expected_error = Error.Okay):
 		
 	return test("test_shr_signed", res, [a, bits], expected_error, expected_result)
 
+def test_factorial(n = 0, expected_error = Error.Okay):
+	args  = [n]
+	res   = int_factorial(*args)
+	expected_result = None
+	if expected_error == Error.Okay:
+		expected_result = math.factorial(n)
+		
+	return test("test_factorial", res, [n], expected_error, expected_result)
+
+
 # TODO(Jeroen): Make sure tests cover edge cases, fast paths, and so on.
 #
 # The last two arguments in tests are the expected error and expected result.
@@ -394,7 +406,10 @@ TESTS = {
 		[ -149195686190273039203651143129455, 12 ],
 		[ 611105530635358368578155082258244262, 12 ],
 		[ 149195686190273039203651143129455, 12 ],
-	]
+	],
+	test_factorial: [
+		[ 12_345 ],
+	],
 }
 
 total_passes   = 0