[Tests] Automatically substitute [[@LINE]] numbers

Tests/Functional/Asynchronous/Misuse/main.swift

@@ -14,23 +14,23 @@
 // CHECK: Test Suite 'MisuseTestCase' started at \d+:\d+:\d+\.\d+
 class MisuseTestCase: XCTestCase {
 // CHECK: Test Case 'MisuseTestCase.test_whenExpectationsAreMade_butNotWaitedFor_fails' started at \d+:\d+:\d+\.\d+
-// CHECK: .*/Tests/Functional/Asynchronous/Misuse/main.swift:21: error: MisuseTestCase.test_whenExpectationsAreMade_butNotWaitedFor_fails : Failed due to unwaited expectations.
+// CHECK: .*/Tests/Functional/Asynchronous/Misuse/main.swift:[[@LINE+4]]: error: MisuseTestCase.test_whenExpectationsAreMade_butNotWaitedFor_fails : Failed due to unwaited expectations.
 // CHECK: Test Case 'MisuseTestCase.test_whenExpectationsAreMade_butNotWaitedFor_fails' failed \(\d+\.\d+ seconds\).
     func test_whenExpectationsAreMade_butNotWaitedFor_fails() {
         self.expectation(withDescription: "the first expectation")
         self.expectation(withDescription: "the second expectation (the file and line number for this one are included in the failure message")
     }
 
 // CHECK: Test Case 'MisuseTestCase.test_whenNoExpectationsAreMade_butTheyAreWaitedFor_fails' started at \d+:\d+:\d+\.\d+
-// CHECK: .*/Tests/Functional/Asynchronous/Misuse/main.swift:28: error: MisuseTestCase.test_whenNoExpectationsAreMade_butTheyAreWaitedFor_fails : API violation - call made to wait without any expectations having been set.
+// CHECK: .*/Tests/Functional/Asynchronous/Misuse/main.swift:[[@LINE+3]]: error: MisuseTestCase.test_whenNoExpectationsAreMade_butTheyAreWaitedFor_fails : API violation - call made to wait without any expectations having been set.
 // CHECK: Test Case 'MisuseTestCase.test_whenNoExpectationsAreMade_butTheyAreWaitedFor_fails' failed \(\d+\.\d+ seconds\).
     func test_whenNoExpectationsAreMade_butTheyAreWaitedFor_fails() {
         self.waitForExpectations(withTimeout: 0.1)
     }
 
 // CHECK: Test Case 'MisuseTestCase.test_whenExpectationIsFulfilledMultipleTimes_fails' started at \d+:\d+:\d+\.\d+
-// CHECK: .*/Tests/Functional/Asynchronous/Misuse/main.swift:38: error: MisuseTestCase.test_whenExpectationIsFulfilledMultipleTimes_fails : API violation - multiple calls made to XCTestExpectation.fulfill\(\) for rob.
-// CHECK: .*/Tests/Functional/Asynchronous/Misuse/main.swift:48: error: MisuseTestCase.test_whenExpectationIsFulfilledMultipleTimes_fails : API violation - multiple calls made to XCTestExpectation.fulfill\(\) for rob.
+// CHECK: .*/Tests/Functional/Asynchronous/Misuse/main.swift:[[@LINE+6]]: error: MisuseTestCase.test_whenExpectationIsFulfilledMultipleTimes_fails : API violation - multiple calls made to XCTestExpectation.fulfill\(\) for rob.
+// CHECK: .*/Tests/Functional/Asynchronous/Misuse/main.swift:[[@LINE+15]]: error: MisuseTestCase.test_whenExpectationIsFulfilledMultipleTimes_fails : API violation - multiple calls made to XCTestExpectation.fulfill\(\) for rob.
 // CHECK: Test Case 'MisuseTestCase.test_whenExpectationIsFulfilledMultipleTimes_fails' failed \(\d+\.\d+ seconds\).
     func test_whenExpectationIsFulfilledMultipleTimes_fails() {
         let expectation = self.expectation(withDescription: "rob")

Tests/Functional/xctest_checker/tests/test_compare.py

@@ -87,5 +87,10 @@ def test_can_explicitly_match_leading_and_trailing_whitespace(self):
         expected = _tmpfile('c: foo\nc: ^ bar \nc: baz $\n')
         compare.compare(actual, expected, check_prefix='c:')
 
+    def test_line_number_substitution(self):
+        actual = _tmpfile('beep 1\nboop 5\n')
+        expected = _tmpfile('c: beep [[@LINE]]\nc: boop [[@LINE+3]]')
+        compare.compare(actual, expected, check_prefix='c: ')
+
 if __name__ == "__main__":
     unittest.main()

Tests/Functional/xctest_checker/xctest_checker/compare.py

@@ -11,6 +11,7 @@
 import re
 
 from .error import XCTestCheckerError
+from .line import replace_offsets
 
 
 def _actual_lines(path):
@@ -40,7 +41,8 @@ def _expected_lines_and_line_numbers(path, check_prefix):
 
             components = line.split(check_prefix)
             if len(components) == 2:
-                yield components[1].strip(), line_number
+                yield (replace_offsets(components[1].strip(), line_number),
+                       line_number)
             elif len(components) > 2:
                 # Include a newline, then the file name and line number in the
                 # exception in order to have it appear as an inline failure in

Tests/Functional/xctest_checker/xctest_checker/line.py

@@ -0,0 +1,41 @@
+# xctest_checker/line.py - Replaces [[@LINE]] with line numbers -*- python -*-
+#
+# This source file is part of the Swift.org open source project
+#
+# Copyright (c) 2014 - 2016 Apple Inc. and the Swift project authors
+# Licensed under Apache License v2.0 with Runtime Library Exception
+#
+# See http://swift.org/LICENSE.txt for license information
+# See http://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+
+import re
+
+
+def replace_offsets(line, line_number):
+    """
+    Replace all line directives in the given line with the given line number.
+
+    Line directives come in two forms:
+    1. "[[@LINE]]", with no offset.
+    2. "[[@LINE+10]]" or "[[@LINE-3]]", with a positive or negative offset.
+    """
+    pattern = re.compile(r'\[\[@LINE(?P<offset>[+-]\d+)?\]\]')
+
+    result = line
+    for match in pattern.finditer(line):
+        offset_string = match.groupdict()['offset']
+        if offset_string is None:
+            offset_string = '0'
+        try:
+            offset = int(offset_string)
+        except ValueError:
+            # Re-raise the error, but with a friendlier explanation of what
+            # went wrong.
+            raise ValueError(
+                'Invalid line offset: "{}". Line offsets must be numerical, '
+                'such as "[[@LINE+10]]" or "[[@LINE-2]]"'.format(
+                    match.group()))
+        result = result.replace(match.group(), str(line_number + offset))
+
+    return result
+