Moved prev_prime tests to test/test_mpz.py

aleaxit · Sep 7, 2023 · 97295d6 · 97295d6
1 parent b24fdea
commit 97295d6
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Showing 3 changed files with 33 additions and 31 deletions.
diff --git a/src/gmpy2_mpz_misc.c b/src/gmpy2_mpz_misc.c
@@ -1505,12 +1505,13 @@ GMPy_MPZ_Function_NextPrime(PyObject *self, PyObject *other)
 
 PyDoc_STRVAR(GMPy_doc_mpz_function_prev_prime,
 "prev_prime(x, /) -> mpz\n\n"
-"Return the previous *probable* prime number < x.");
+"Return the previous *probable* prime number < x.\n"
+"Only present when compiled with GMP 6.3.0 or later.");
 
+#if (__GNU_MP_VERSION > 6) || (__GNU_MP_VERSION == 6 &&  __GNU_MP_VERSION_MINOR >= 3)
 static PyObject *
 GMPy_MPZ_Function_PrevPrime(PyObject *self, PyObject *other)
 {
-    #if (__GNU_MP_VERSION > 6) || (__GNU_MP_VERSION == 6 &&  __GNU_MP_VERSION_MINOR >= 3)
         MPZ_Object *result;
 
         if(MPZ_Check(other)) {
@@ -1520,8 +1521,9 @@ GMPy_MPZ_Function_PrevPrime(PyObject *self, PyObject *other)
                 /* LCOV_EXCL_STOP */
             }
             if (!mpz_prevprime(result->z, MPZ(other))) {
-                /* no previous prime, default to 2 in this case */
-                mpz_set_ui(result->z, 2);
+                /* no previous prime, raise value error. */
+                VALUE_ERROR("x must be >= 3");
+                return NULL;
             }
         }
         else {
@@ -1531,16 +1533,15 @@ GMPy_MPZ_Function_PrevPrime(PyObject *self, PyObject *other)
             }
             else {
                 if (!mpz_prevprime(result->z, result->z)) {
-                    /* no previous prime, default to 2 in this case */
-                    mpz_set_ui(result->z, 2);
+                    /* no previous prime, raise value error. */
+                    VALUE_ERROR("x must be >= 3");
+                    return NULL;
                 }
             }
         }
         return (PyObject*)result;
-    #endif
-
-    Py_RETURN_NOTIMPLEMENTED;
 }
+#endif
 
 
 PyDoc_STRVAR(GMPy_doc_mpz_function_jacobi,

diff --git a/test/test_gmpy2_mpz_misc.txt b/test/test_gmpy2_mpz_misc.txt
@@ -657,27 +657,6 @@ mpz(1000003)
 >>> gmpy2.next_prime(2357*7069-1) == 2357*7069
 False
 
-Test prev_prime
----------------
->>> gmpy2.prev_prime('a')
-Traceback (most recent call last):
-  ...
-TypeError:
->>> gmpy2.prev_prime(2)
-mpz(2)
->>> gmpy2.prev_prime(mpz(3))
-mpz(2)
->>> gmpy2.prev_prime(3)
-mpz(2)
->>> gmpy2.prev_prime(1000004)
-mpz(1000003)
->>> gmpy2.prev_prime(1000033)
-mpz(1000003)
->>> gmpy2.prev_prime(-100)
-mpz(2)
->>> gmpy2.prev_prime(1)
-mpz(2)
-
 Test iroot
 ----------
 >>> gmpy2.iroot(1,2,3)

diff --git a/test/test_mpz.py b/test/test_mpz.py
@@ -8,7 +8,8 @@
 from pytest import raises
 
 from gmpy2 import (mpz, pack, unpack, cmp, cmp_abs, to_binary, from_binary,
-                   random_state, mpz_random, mpz_urandomb, mpz_rrandomb)
+                   random_state, mpz_random, mpz_urandomb, mpz_rrandomb,
+                   prev_prime)
 from supportclasses import a, b, c, d, z, q
 
 
@@ -309,3 +310,24 @@ def test_mpz_urandomb():
 def test_mpz_rrandomb():
     assert (mpz_rrandomb(random_state(42), 64).digits(2) ==
             '1111111111111111111111111100000000111111111111111111000000000000')
+
+
+def test_prev_prime():
+    assert prev_prime(3) == mpz(2)
+    assert prev_prime(4) == mpz(3)
+    assert prev_prime(5) == mpz(3)
+    assert prev_prime(6) == mpz(5)
+    assert prev_prime(1000004) == mpz(1000003)
+    assert prev_prime(1000033) == mpz(1000003)
+
+    with raises(ValueError):
+        prev_prime(-100)
+
+    with raises(ValueError):
+        prev_prime(2)
+
+    with raises(TypeError):
+        prev_prime('a')
+
+    with raises(TypeError):
+        prev_prime(4.5)