fix NO_PREREQ_INSTALL

pavelib/paver_tests/test_prereqs.py

+
+import os
+import unittest
+from pavelib.prereqs import no_prereq_install
+
+
+class TestPaverPrereqInstall(unittest.TestCase):
+
+    def check_val(self, set_val, expected_val):
+        _orig_environ = dict(os.environ)
+        os.environ['NO_PREREQ_INSTALL'] = set_val
+        self.assertEqual(
+            no_prereq_install(),
+            expected_val,
+            'NO_PREREQ_INSTALL is set to {}, but we read it as {}'.format(
+                set_val, expected_val),
+        )
+
+        # Reset Environment back to original state
+        os.environ.clear()
+        os.environ.update(_orig_environ)
+
+    def test_no_prereq_install_true(self):
+        self.check_val('true', True)
+
+    def test_no_prereq_install_false(self):
+        self.check_val('false', False)
+
+    def test_no_prereq_install_True(self):
+        self.check_val('True', True)
+
+    def test_no_prereq_install_False(self):
+        self.check_val('False', False)
+
+    def test_no_prereq_install_0(self):
+        self.check_val('0', False)
+
+    def test_no_prereq_install_1(self):
+        self.check_val('1', True)
+

pavelib/prereqs.py

@@ -27,6 +27,25 @@ if os.path.exists(PRIVATE_REQS):
     PYTHON_REQ_FILES.append(PRIVATE_REQS)
 
 
+def no_prereq_install():
+    """
+    Determine if NO_PREREQ_INSTALL should be truthy or falsy.
+    """
+    vals = {
+        '0': False,
+        '1': True,
+        'true': True,
+        'false': False,
+    }
+
+    val = os.environ.get("NO_PREREQ_INSTALL", 'False').lower()
+
+    try:
+        return vals[val]
+    except:
+        return False
+
+
 def compute_fingerprint(path_list):
     """
     Hash the contents of all the files and directories in `path_list`.
@@ -125,7 +144,7 @@ def install_ruby_prereqs():
     """
     Installs Ruby prereqs
     """
-    if os.environ.get("NO_PREREQ_INSTALL", False):
+    if no_prereq_install():
         return
 
     prereq_cache("Ruby prereqs", ["Gemfile"], ruby_prereqs_installation)
@@ -136,7 +155,7 @@ def install_node_prereqs():
     """
     Installs Node prerequisites
     """
-    if os.environ.get("NO_PREREQ_INSTALL", False):
+    if no_prereq_install():
         return
 
     prereq_cache("Node prereqs", ["package.json"], node_prereqs_installation)
@@ -147,7 +166,7 @@ def install_python_prereqs():
     """
     Installs Python prerequisites
     """
-    if os.environ.get("NO_PREREQ_INSTALL", False):
+    if no_prereq_install():
         return
 
     prereq_cache("Python prereqs", PYTHON_REQ_FILES + [sysconfig.get_python_lib()], python_prereqs_installation)
@@ -158,7 +177,7 @@ def install_prereqs():
     """
     Installs Ruby, Node and Python prerequisites
     """
-    if os.environ.get("NO_PREREQ_INSTALL", False):
+    if no_prereq_install():
         return
 
     install_ruby_prereqs()