From: Richard Kreckel <kreckel@ginac.de>
Date: Sun, 28 Jun 2020 15:21:33 +0000 (+0200)
Subject: Add exam for exam_common_factors.
X-Git-Tag: release_1-7-10~1
X-Git-Url: https://www.ginac.de/ginac.git//ginac.git?p=ginac.git;a=commitdiff_plain;h=1193f765c62171a4267ef0138ecc22c875a7daf4

Add exam for exam_common_factors.

Including a case involving a hidden zero to catch errors like the one fixed
in 5f7f81ad35a, as suggested by Alexey Sheplyakov <asheplyakov@yandex.ru>.
---

diff --git a/check/CMakeLists.txt b/check/CMakeLists.txt
index c229a818..9d9e0839 100644
--- a/check/CMakeLists.txt
+++ b/check/CMakeLists.txt
@@ -19,6 +19,7 @@ set(ginac_tests
 	exam_inifcns_nstdsums
 	exam_differentiation
 	exam_polygcd
+	exam_collect_common_factors
 	exam_normalization
 	exam_factor
 	exam_pseries
diff --git a/check/Makefile.am b/check/Makefile.am
index e8adab07..8d00fdb1 100644
--- a/check/Makefile.am
+++ b/check/Makefile.am
@@ -16,6 +16,7 @@ EXAMS = exam_paranoia \
 	exam_inifcns_nstdsums \
 	exam_differentiation  \
 	exam_polygcd  \
+	exam_collect_common_factors \
 	exam_normalization  \
 	exam_factor \
 	exam_pseries  \
@@ -114,6 +115,9 @@ exam_differentiation_LDADD = ../ginac/libginac.la
 exam_polygcd_SOURCES = exam_polygcd.cpp
 exam_polygcd_LDADD = ../ginac/libginac.la
 
+exam_collect_common_factors_SOURCES = exam_collect_common_factors.cpp
+exam_collect_common_factors_LDADD = ../ginac/libginac.la
+
 exam_normalization_SOURCES = exam_normalization.cpp
 exam_normalization_LDADD = ../ginac/libginac.la
 
diff --git a/check/exam_collect_common_factors.cpp b/check/exam_collect_common_factors.cpp
new file mode 100644
index 00000000..520e0d84
--- /dev/null
+++ b/check/exam_collect_common_factors.cpp
@@ -0,0 +1,59 @@
+#include <iostream>
+#include "ginac.h"
+using namespace std;
+using namespace GiNaC;
+
+static unsigned exam_collect_common_factors_simple()
+{
+	unsigned result = 0;
+	symbol a("a"), b("b"), c("c"), x("x"), y("y");
+	ex ei, ef, ref;
+
+	ei = a*x + a*y;
+	ef = collect_common_factors(ei);
+	ref = (x+y)*a;
+	if (ef != ref) {
+		clog << "ERROR: collect_common_factors(" << ei << ") returned "
+		     << ef << ", not " << ref << '.' << endl;
+		++result;
+	}
+
+	ei = a*x*x + 2*a*x*y + a*y*y;
+	ef = collect_common_factors(ei);
+	ref = a*(x*x + 2*x*y + y*y);
+	if (ef != ref) {
+		clog << "ERROR: collect_common_factors(" << ei << ") returned "
+		     << ef << ", not " << ref << '.' << endl;
+		++result;
+	}
+
+	return result;
+}
+
+static unsigned exam_collect_common_factors_zero()
+{
+	// r = 0 = c*0 = c*(x + 1 - 1 - x) = c*(x + 1) - c - c*x
+	// e = a*r - b*r
+	symbol a("a"), b("b"), c("c"), x("x");
+
+	ex r = c*(x+1) - c - c*x;
+	ex ei = a*r + b*r;
+	ex ef = collect_common_factors(ei);
+	if (!ef.is_zero()) {
+		clog << "ERROR: " << ei << " should be 0, got " << ef << " instead." << endl;
+		return 1;
+	}
+	return 0;
+}
+
+int main(int argc, char** argv)
+{
+	int result = 0;
+
+	cout << "examining collect_common_factors" << flush;
+
+	result += exam_collect_common_factors_simple();  cout << '.' << flush;
+	result += exam_collect_common_factors_zero();  cout << '.' << flush;
+
+	return result;
+}