1 files changed, 44 insertions, 0 deletions
diff --git a/numpy/distutils/tests/test_fcompiler.py b/numpy/distutils/tests/test_fcompiler.py
new file mode 100644
index 000000000..95e44b051
--- /dev/null
+++ b/numpy/distutils/tests/test_fcompiler.py
@@ -0,0 +1,44 @@
+from __future__ import division, absolute_import, print_function
+
+from numpy.testing import assert_
+import numpy.distutils.fcompiler
+
+customizable_flags = [
+    ('f77', 'F77FLAGS'),
+    ('f90', 'F90FLAGS'),
+    ('free', 'FREEFLAGS'),
+    ('arch', 'FARCH'),
+    ('debug', 'FDEBUG'),
+    ('flags', 'FFLAGS'),
+    ('linker_so', 'LDFLAGS'),
+]
+
+
+def test_fcompiler_flags(monkeypatch):
+    monkeypatch.setenv('NPY_DISTUTILS_APPEND_FLAGS', '0')
+    fc = numpy.distutils.fcompiler.new_fcompiler(compiler='none')
+    flag_vars = fc.flag_vars.clone(lambda *args, **kwargs: None)
+
+    for opt, envvar in customizable_flags:
+        new_flag = '-dummy-{}-flag'.format(opt)
+        prev_flags = getattr(flag_vars, opt)
+
+        monkeypatch.setenv(envvar, new_flag)
+        new_flags = getattr(flag_vars, opt)
+        monkeypatch.delenv(envvar)
+        assert_(new_flags == [new_flag])
+
+    monkeypatch.setenv('NPY_DISTUTILS_APPEND_FLAGS', '1')
+
+    for opt, envvar in customizable_flags:
+        new_flag = '-dummy-{}-flag'.format(opt)
+        prev_flags = getattr(flag_vars, opt)
+
+        monkeypatch.setenv(envvar, new_flag)
+        new_flags = getattr(flag_vars, opt)
+        monkeypatch.delenv(envvar)
+        if prev_flags is None:
+            assert_(new_flags == [new_flag])
+        else:
+            assert_(new_flags == prev_flags + [new_flag])
+