Abstract out path prefix comparisons

4 files changed, 76 insertions, 6 deletions

diff --git a/gemato/manifest.py b/gemato/manifest.py
index 065b852..c1a605e 100644
--- a/gemato/manifest.py
+++ b/gemato/manifest.py
@@ -6,6 +6,8 @@
 import datetime
 import os.path
 
+import gemato.util
+
 
 class ManifestSyntaxError(Exception):
     def __init__(self, message):
@@ -257,7 +259,7 @@ class ManifestEntryAUX(ManifestFileEntry):
 
     def to_list(self):
         ret = super(ManifestEntryAUX, self).to_list(self.tag)
-        assert ret[1].startswith('files/')
+        assert gemato.util.path_inside_dir(ret[1], 'files')
         ret[1] = ret[1][6:]
         return ret
 
@@ -335,7 +337,7 @@ class ManifestFile(object):
             if isinstance(e, ManifestEntryIGNORE):
                 # ignore matches recursively, so we process it separately
                 # py<3.5 does not have os.path.commonpath()
-                if (path + '/').startswith(e.path + '/'):
+                if gemato.util.path_starts_with(path, e.path):
                     return e
             elif isinstance(e, ManifestEntryDIST):
                 # distfiles are not local files, so skip them
@@ -367,7 +369,7 @@ class ManifestFile(object):
         for e in self.entries:
             if isinstance(e, ManifestEntryMANIFEST):
                 mdir = os.path.dirname(e.path)
-                if path.startswith(mdir + '/'):
+                if gemato.util.path_inside_dir(path, mdir):
                     yield e
 
 
diff --git a/gemato/recursiveloader.py b/gemato/recursiveloader.py
index 4c20d6d..8003245 100644
--- a/gemato/recursiveloader.py
+++ b/gemato/recursiveloader.py
@@ -8,6 +8,7 @@ import os.path
 import weakref
 
 import gemato.manifest
+import gemato.util
 import gemato.verify
 
 
@@ -48,7 +49,7 @@ class ManifestRecursiveLoader(object):
         """
         for k, v in self.loaded_manifests.items():
             d = os.path.dirname(k)
-            if not d or (path + '/').startswith(d + '/'):
+            if gemato.util.path_starts_with(path, d):
                 yield (d, v)
 
     def load_manifests_for_path(self, path):
@@ -66,7 +67,7 @@ class ManifestRecursiveLoader(object):
                     if mpath in self.loaded_manifests:
                         continue
                     mdir = os.path.dirname(mpath)
-                    if not mdir or path.startswith(mdir + '/'):
+                    if gemato.util.path_starts_with(path, mdir):
                         to_load.append((mpath, e))
             if not to_load:
                 break
@@ -99,7 +100,7 @@ class ManifestRecursiveLoader(object):
                     # ignore matches recursively, so we process it separately
                     # py<3.5 does not have os.path.commonpath()
                     fullpath = os.path.join(relpath, e.path)
-                    if (path + '/').startswith(fullpath + '/'):
+                    if gemato.util.path_starts_with(path, fullpath):
                         return e
                 elif isinstance(e, gemato.manifest.ManifestEntryDIST):
                     # distfiles are not local files, so skip them
diff --git a/gemato/util.py b/gemato/util.py
new file mode 100644
index 0000000..e136c5c
--- /dev/null
+++ b/gemato/util.py
@@ -0,0 +1,21 @@
+# gemato: Utility functions
+# vim:fileencoding=utf-8
+# (c) 2017 Michał Górny
+# Licensed under the terms of 2-clause BSD license
+
+
+def path_starts_with(path, prefix):
+    """
+    Returns True if the specified @path starts with the @prefix,
+    performing component-wide comparison. Otherwise returns False.
+    """
+    return prefix == "" or (path + "/").startswith(prefix.rstrip("/") + "/")
+
+
+def path_inside_dir(path, directory):
+    """
+    Returns True if the specified @path is inside @directory,
+    performing component-wide comparison. Otherwise returns False.
+    """
+    return ((directory == "" and path != "")
+            or path.rstrip("/").startswith(directory.rstrip("/") + "/"))
diff --git a/tests/test_util.py b/tests/test_util.py
new file mode 100644
index 0000000..41aa34c
--- /dev/null
+++ b/tests/test_util.py
@@ -0,0 +1,46 @@
+# gemato: Utility function tests
+# vim:fileencoding=utf-8
+# (c) 2017 Michał Górny
+# Licensed under the terms of 2-clause BSD license
+
+import unittest
+
+import gemato.util
+
+
+class UtilityTestCase(unittest.TestCase):
+    def test_path_starts_with(self):
+        self.assertTrue(gemato.util.path_starts_with("", ""))
+        self.assertTrue(gemato.util.path_starts_with("foo", ""))
+        self.assertTrue(gemato.util.path_starts_with("foo/", ""))
+        self.assertTrue(gemato.util.path_starts_with("foo/bar", ""))
+        self.assertTrue(gemato.util.path_starts_with("bar", ""))
+        self.assertTrue(gemato.util.path_starts_with("bar/", ""))
+        self.assertTrue(gemato.util.path_starts_with("bar/bar", ""))
+        self.assertTrue(gemato.util.path_starts_with("foo", "foo"))
+        self.assertTrue(gemato.util.path_starts_with("foo/", "foo"))
+        self.assertTrue(gemato.util.path_starts_with("foo/bar", "foo"))
+        self.assertFalse(gemato.util.path_starts_with("bar", "foo"))
+        self.assertFalse(gemato.util.path_starts_with("fooo", "foo"))
+        self.assertFalse(gemato.util.path_starts_with("foo.", "foo"))
+        self.assertTrue(gemato.util.path_starts_with("foo", "foo/"))
+        self.assertTrue(gemato.util.path_starts_with("foo/", "foo/"))
+        self.assertTrue(gemato.util.path_starts_with("foo/bar", "foo/bar/"))
+
+    def test_path_inside_dir(self):
+        self.assertFalse(gemato.util.path_inside_dir("", ""))
+        self.assertTrue(gemato.util.path_inside_dir("foo", ""))
+        self.assertTrue(gemato.util.path_inside_dir("foo/", ""))
+        self.assertTrue(gemato.util.path_inside_dir("foo/bar", ""))
+        self.assertTrue(gemato.util.path_inside_dir("bar", ""))
+        self.assertTrue(gemato.util.path_inside_dir("bar/", ""))
+        self.assertTrue(gemato.util.path_inside_dir("bar/bar", ""))
+        self.assertFalse(gemato.util.path_inside_dir("foo", "foo"))
+        self.assertFalse(gemato.util.path_inside_dir("foo/", "foo"))
+        self.assertTrue(gemato.util.path_inside_dir("foo/bar", "foo"))
+        self.assertFalse(gemato.util.path_inside_dir("bar", "foo"))
+        self.assertFalse(gemato.util.path_inside_dir("fooo", "foo"))
+        self.assertFalse(gemato.util.path_inside_dir("foo.", "foo"))
+        self.assertFalse(gemato.util.path_inside_dir("foo", "foo/"))
+        self.assertFalse(gemato.util.path_inside_dir("foo/", "foo/"))
+        self.assertFalse(gemato.util.path_inside_dir("foo/bar", "foo/bar/"))