Port dart:io Path tests to package:path.

pkg/path/test/relative_test.dart

+// Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+//
+// Test "relative" on all styles of path.Builder, on all platforms.
+
+import "package:unittest/unittest.dart";
+import "package:path/path.dart" as path;
+
+void main() {
+  test("test relative", () {
+    relativeTest(new path.Builder(style: path.Style.posix, root: '.'), '');
+    relativeTest(new path.Builder(style: path.Style.posix, root: '/'), '');
+    relativeTest(new path.Builder(style: path.Style.windows, root: 'd:/'),
+                 'c:');

[nweiz, 2013/07/22 21:00:33]

It seems weird to me that the prefix here is "c:" when the actual root prefix on
Windows is "c:\" (including the "\"). It's made more weird by the fact that
"file:///" is a full prefix, and adding an additional "/" will result in a
redundant extra "/".

[Bill Hesse, 2013/07/23 16:07:00]

The prefix for the URL tests is 'http://myserver', not 'file:///'.  'file:///'
is the builder's root.

Changed all the prefixes to include the separator.

+    relativeTest(new path.Builder(style: path.Style.windows, root: '.'), 'c:');
+    relativeTest(new path.Builder(style: path.Style.url, root: 'file:///'),
+                 'http://myserver');
+    relativeTest(new path.Builder(style: path.Style.url, root: '.'),
+                 'http://myserver');
+    relativeTest(new path.Builder(style: path.Style.url, root: 'file:///'), '');
+    relativeTest(new path.Builder(style: path.Style.url, root: '.'), '');
+  });
+}
+
+void relativeTest(path.Builder builder, String prefix) {
+  var isRelative = (builder.root == '.');
+  // Cases where the arguments are absolute paths.
+  test(result, p, from) {

[nweiz, 2013/07/22 21:00:33]

Calling this [test] is confusing given that [test] is a function defined by
unittest and used elsewhere in this file. Maybe something like "expectRelative"?

[p] is also a non-descriptive name. Maybe "pth"?

[Bill Hesse, 2013/07/23 16:07:00]

Done.

+    expect(builder.normalize(result), builder.relative(p, from: from));
+  }
+
+  test('c/d', '$prefix/a/b/c/d', '$prefix/a/b');
+  test('c/d', '$prefix/a/b/c/d', '$prefix/a/b/');
+  test('.', '$prefix/a', '$prefix/a');
+  // Trailing slashes in the inputs have no effect.
+  test('../../z/x/y', '$prefix/a/b/z/x/y', '$prefix/a/b/c/d/');
+  test('../../z/x/y', '$prefix/a/b/z/x/y', '$prefix/a/b/c/d');
+  test('../../z/x/y', '$prefix/a/b/z/x/y/', '$prefix/a/b/c/d');
+  test('../../../z/x/y', '$prefix/z/x/y', '$prefix/a/b/c');
+  test('../../../z/x/y', '$prefix/z/x/y', '$prefix/a/b/c/');
+
+  // Cases where the arguments are relative paths.
+  test('c/d', 'a/b/c/d', 'a/b');
+  test('.', 'a/b/c', 'a/b/c');
+  test('.', 'a/d/../b/c', 'a/b/c/');
+  test('.', '', '');
+  test('.', '.', '');
+  test('.', '', '.');
+  test('.', '.', '.');
+  test('.', '..', '..');
+  if (isRelative) test('..', '..', '.');
+  test('a', 'a', '');
+  test('a', 'a', '.');
+  test('..', '.', 'a');
+  test('.', 'a/b/f/../c', 'a/e/../b/c');
+  test('d', 'a/b/f/../c/d', 'a/e/../b/c');
+  test('..', 'a/b/f/../c', 'a/e/../b/c/e/');
+  test('../..', '', 'a/b/');
+  if (isRelative) test('../../..', '..', 'a/b/');
+  test('../b/c/d', 'b/c/d/', 'a/');
+  test('../a/b/c', 'x/y/a//b/./f/../c', 'x//y/z');
+
+  // Case where from is an exact substring of path.
+  test('a/b', '$prefix/x/y//a/b', '$prefix/x/y/');
+  test('a/b', 'x/y//a/b', 'x/y/');
+  test('../ya/b', '$prefix/x/ya/b', '$prefix/x/y');
+  test('../ya/b', 'x/ya/b', 'x/y');
+  test('../b', 'x/y/../b', 'x/y/.');
+  test('a/b/c', 'x/y/a//b/./f/../c', 'x/y');
+  test('.', '$prefix/x/y//', '$prefix/x/y/');
+  test('.', '$prefix/x/y/', '$prefix/x/y');
+
+  // Should always throw - no relative path can be constructed.
+  if (isRelative) {
+    expect(() => builder.relative('.', from: '..'), throws);
+    expect(() => builder.relative('a/b', from: '../../d'), throws);
+    expect(() => builder.relative('a/b', from: '$prefix/a/b'), throws);
+    // An absolute path relative from a relative path returns the absolute path.
+    test('$prefix/a/b', '$prefix/a/b', 'c/d');
+  }
+}