Add algorithm for testing Project Euler solutions

.travis.yml

@@ -12,6 +12,7 @@ jobs:
         - black --check . || true 
         - flake8 --ignore=E203,W503 --max-complexity=25 --max-line-length=88 --statistics --count .
         - scripts/validate_filenames.py  # no uppercase, no spaces, in a directory
+        - project_euler/validate_solutions.py  # test project Euler solutions
         - pip install -r requirements.txt  # fast fail on black, flake8, validate_filenames
       script:
         - mypy --ignore-missing-imports . || true  # https://github.com/python/mypy/issues/7907

project_euler/validate_solutions.py

@@ -0,0 +1,231 @@
+#!/usr/bin/env python3
+import importlib.util
+import pathlib
+from collections import namedtuple
+
+# CamelCase as this returns a class object
+QuesAndAns = namedtuple("QuesAndAns", "question answer")
+
+ques_08 = (
+    "73167176531330624919225119674426574742355349194934"
+    "96983520312774506326239578318016984801869478851843"
+    "85861560789112949495459501737958331952853208805511"
+    "12540698747158523863050715693290963295227443043557"
+    "66896648950445244523161731856403098711121722383113"
+    "62229893423380308135336276614282806444486645238749"
+    "30358907296290491560440772390713810515859307960866"
+    "70172427121883998797908792274921901699720888093776"
+    "65727333001053367881220235421809751254540594752243"
+    "52584907711670556013604839586446706324415722155397"
+    "53697817977846174064955149290862569321978468622482"
+    "83972241375657056057490261407972968652414535100474"
+    "82166370484403199890008895243450658541227588666881"
+    "16427171479924442928230863465674813919123162824586"
+    "17866458359124566529476545682848912883142607690042"
+    "24219022671055626321111109370544217506941658960408"
+    "07198403850962455444362981230987879927244284909188"
+    "84580156166097919133875499200524063689912560717606"
+    "05886116467109405077541002256983155200055935729725"
+    "71636269561882670428252483600823257530420752963450"
+)
+
+ques_13 = [
+    37107287533902102798797998220837590246510135740250,
+    46376937677490009712648124896970078050417018260538,
+    74324986199524741059474233309513058123726617309629,
+    91942213363574161572522430563301811072406154908250,
+    23067588207539346171171980310421047513778063246676,
+    89261670696623633820136378418383684178734361726757,
+    28112879812849979408065481931592621691275889832738,
+    44274228917432520321923589422876796487670272189318,
+    47451445736001306439091167216856844588711603153276,
+    70386486105843025439939619828917593665686757934951,
+    62176457141856560629502157223196586755079324193331,
+    64906352462741904929101432445813822663347944758178,
+    92575867718337217661963751590579239728245598838407,
+    58203565325359399008402633568948830189458628227828,
+    80181199384826282014278194139940567587151170094390,
+    35398664372827112653829987240784473053190104293586,
+    86515506006295864861532075273371959191420517255829,
+    71693888707715466499115593487603532921714970056938,
+    54370070576826684624621495650076471787294438377604,
+    53282654108756828443191190634694037855217779295145,
+    36123272525000296071075082563815656710885258350721,
+    45876576172410976447339110607218265236877223636045,
+    17423706905851860660448207621209813287860733969412,
+    81142660418086830619328460811191061556940512689692,
+    51934325451728388641918047049293215058642563049483,
+    62467221648435076201727918039944693004732956340691,
+    15732444386908125794514089057706229429197107928209,
+    55037687525678773091862540744969844508330393682126,
+    18336384825330154686196124348767681297534375946515,
+    80386287592878490201521685554828717201219257766954,
+    78182833757993103614740356856449095527097864797581,
+    16726320100436897842553539920931837441497806860984,
+    48403098129077791799088218795327364475675590848030,
+    87086987551392711854517078544161852424320693150332,
+    59959406895756536782107074926966537676326235447210,
+    69793950679652694742597709739166693763042633987085,
+    41052684708299085211399427365734116182760315001271,
+    65378607361501080857009149939512557028198746004375,
+    35829035317434717326932123578154982629742552737307,
+    94953759765105305946966067683156574377167401875275,
+    88902802571733229619176668713819931811048770190271,
+    25267680276078003013678680992525463401061632866526,
+    36270218540497705585629946580636237993140746255962,
+    24074486908231174977792365466257246923322810917141,
+    91430288197103288597806669760892938638285025333403,
+    34413065578016127815921815005561868836468420090470,
+    23053081172816430487623791969842487255036638784583,
+    11487696932154902810424020138335124462181441773470,
+    63783299490636259666498587618221225225512486764533,
+    67720186971698544312419572409913959008952310058822,
+    95548255300263520781532296796249481641953868218774,
+    76085327132285723110424803456124867697064507995236,
+    37774242535411291684276865538926205024910326572967,
+    23701913275725675285653248258265463092207058596522,
+    29798860272258331913126375147341994889534765745501,
+    18495701454879288984856827726077713721403798879715,
+    38298203783031473527721580348144513491373226651381,
+    34829543829199918180278916522431027392251122869539,
+    40957953066405232632538044100059654939159879593635,
+    29746152185502371307642255121183693803580388584903,
+    41698116222072977186158236678424689157993532961922,
+    62467957194401269043877107275048102390895523597457,
+    23189706772547915061505504953922979530901129967519,
+    86188088225875314529584099251203829009407770775672,
+    11306739708304724483816533873502340845647058077308,
+    82959174767140363198008187129011875491310547126581,
+    97623331044818386269515456334926366572897563400500,
+    42846280183517070527831839425882145521227251250327,
+    55121603546981200581762165212827652751691296897789,
+    32238195734329339946437501907836945765883352399886,
+    75506164965184775180738168837861091527357929701337,
+    62177842752192623401942399639168044983993173312731,
+    32924185707147349566916674687634660915035914677504,
+    99518671430235219628894890102423325116913619626622,
+    73267460800591547471830798392868535206946944540724,
+    76841822524674417161514036427982273348055556214818,
+    97142617910342598647204516893989422179826088076852,
+    87783646182799346313767754307809363333018982642090,
+    10848802521674670883215120185883543223812876952786,
+    71329612474782464538636993009049310363619763878039,
+    62184073572399794223406235393808339651327408011116,
+    66627891981488087797941876876144230030984490851411,
+    60661826293682836764744779239180335110989069790714,
+    85786944089552990653640447425576083659976645795096,
+    66024396409905389607120198219976047599490197230297,
+    64913982680032973156037120041377903785566085089252,
+    16730939319872750275468906903707539413042652315011,
+    94809377245048795150954100921645863754710598436791,
+    78639167021187492431995700641917969777599028300699,
+    15368713711936614952811305876380278410754449733078,
+    40789923115535562561142322423255033685442488917353,
+    44889911501440648020369068063960672322193204149535,
+    41503128880339536053299340368006977710650566631954,
+    81234880673210146739058568557934581403627822703280,
+    82616570773948327592232845941706525094512325230608,
+    22918802058777319719839450180888072429661980811197,
+    77158542502016545090413245809786882778948721859617,
+    72107838435069186155435662884062257473692284509516,
+    20849603980134001723930671666823555245252804609722,
+    53503534226472524250874054075591789781264330331690,
+]
+
+# Keep the answer part in str for consistency as some problems could output in str
+# Problem 329: 199740353/29386561536000 (Format for this answer is a/b)
+# https://github.com/nayuki/Project-Euler-solutions/blob/master/Answers.txt#L191
+ANSWERS = {
+    1: QuesAndAns(1000, "233168"),
+    2: QuesAndAns(4_000_000, "4613732"),
+    3: QuesAndAns(600851475143, "6857"),
+    4: QuesAndAns(None, "906609"),
+    5: QuesAndAns(20, "232792560"),
+    6: QuesAndAns(100, "25164150"),
+    7: QuesAndAns(10001, "104743"),
+    8: QuesAndAns(ques_08, "23514624000"),
+    9: QuesAndAns(1000, "31875000"),
+    10: QuesAndAns(2_000_000, "142913828922"),
+    11: QuesAndAns(None, "70600674"),
+    12: QuesAndAns(None, "76576500"),
+    13: QuesAndAns(ques_13, "5537376230"),
+    14: QuesAndAns(1_000_000, "837799"),
+    15: QuesAndAns(None, "137846528820"),
+    16: QuesAndAns(1000, "1366"),
+    17: QuesAndAns(1000, "21124"),
+    18: QuesAndAns(None, "1074"),
+    19: QuesAndAns(None, "171"),
+}
+
+PROJECT_EULER_PATH = pathlib.Path.cwd().joinpath("project_euler")
+
+
+def generate_solution_modules(dir_path: pathlib.Path):
+    # Iterating over every file or directory
+    for file_path in dir_path.iterdir():
+        if file_path.suffix != ".py" or file_path.name.startswith(("_", "test")):
+            continue
+        # Importing the source file through the given path
+        # https://docs.python.org/3/library/importlib.html#importing-a-source-file-directly
+        spec = importlib.util.spec_from_file_location(file_path.name, str(file_path))
+        module = importlib.util.module_from_spec(spec)
+        spec.loader.exec_module(module)
+        yield module
+
+
+def test_project_euler() -> int:
+    wrong_answer, no_solution, solution_args = [[] for _ in range(3)]
+    for problem_number, ques_ans in ANSWERS.items():
+        parameter, expected = ques_ans.question, ques_ans.answer
+        problem_dir = PROJECT_EULER_PATH.joinpath(f"problem_{problem_number:02}")
+        # By checking if it's a directory we can write all the problem number and
+        # answer pair in ANSWERS variable and not worry whether it is actually
+        # present in the 'project_euler' directory
+        if problem_dir.is_dir():
+            for solution_module in generate_solution_modules(problem_dir):
+                try:
+                    answer = str(solution_module.solution())
+                    if answer != expected:
+                        wrong_answer.append(
+                            f"problem_{problem_number:02}/{solution_module.__name__}: "
+                            f"Expected {expected} but got {answer}"
+                        )
+                # TypeError: If solution() requires arguments
+                # AttributeError: If the module has no attribute called 'solution'
+                except AttributeError as err:
+                    no_solution.append(
+                        f"problem_{problem_number:02}/{solution_module.__name__}: {err}"
+                    )
+                except TypeError as err:
+                    if parameter:
+                        answer = str(solution_module.solution(parameter))
+                        if answer != expected:
+                            wrong_answer.append(
+                                f"problem_{problem_number:02}/{solution_module.__name__}: "
+                                f"Expected {expected} but got {answer}"
+                            )
+                    else:
+                        solution_args.append(
+                            f"problem_{problem_number:02}/{solution_module.__name__}: {err}"
+                        )
+    if wrong_answer:
+        print(f"{len(wrong_answer)} files contain wrong answers:\n")
+        print("\n".join(wrong_answer) + "\n")
+    if solution_args:
+        print(
+            f"{len(solution_args)} "
+            f"files require positional arguments for solution() function:\n"
+        )
+        print("\n".join(solution_args) + "\n")
+    if no_solution:
+        print(f"{len(no_solution)} files have no solution() function:\n")
+        print("\n".join(no_solution) + "\n")
+    return len(wrong_answer + solution_args + no_solution)
+
+
+if __name__ == "__main__":
+    exit_code = test_project_euler()
+    if exit_code:
+        import sys
+
+        sys.exit(exit_code)