[Testing] Move clangd::Annotations to llvm testing support

Summary:
Annotations allow writing nice-looking unit test code when one needs
access to locations from the source code, e.g. running code completion
at particular offsets in a file. See comments in Annotations.cpp for
more details on the API.

Also got rid of a duplicate annotations parsing code in clang's code
complete tests.

Reviewers: gribozavr, sammccall

Reviewed By: gribozavr

Subscribers: mgorny, hiraditya, ioeric, MaskRay, jkorous, arphaman, kadircet, jdoerfert, cfe-commits, llvm-commits

Tags: #clang, #llvm

Differential Revision: https://reviews.llvm.org/D59814

llvm-svn: 359179
diff --git a/llvm/unittests/Support/AnnotationsTest.cpp b/llvm/unittests/Support/AnnotationsTest.cpp
new file mode 100644
index 0000000..bf66f17
--- /dev/null
+++ b/llvm/unittests/Support/AnnotationsTest.cpp
@@ -0,0 +1,112 @@
+//===----- unittests/AnnotationsTest.cpp ----------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+#include "llvm/Testing/Support/Annotations.h"
+#include "gmock/gmock.h"
+#include "gtest/gtest.h"
+
+using ::testing::ElementsAre;
+using ::testing::IsEmpty;
+
+namespace {
+llvm::Annotations::Range range(size_t Begin, size_t End) {
+  llvm::Annotations::Range R;
+  R.Begin = Begin;
+  R.End = End;
+  return R;
+}
+
+TEST(AnnotationsTest, CleanedCode) {
+  EXPECT_EQ(llvm::Annotations("foo^bar$nnn[[baz$^[[qux]]]]").code(),
+            "foobarbazqux");
+}
+
+TEST(AnnotationsTest, Points) {
+  // A single point.
+  EXPECT_EQ(llvm::Annotations("^ab").point(), 0u);
+  EXPECT_EQ(llvm::Annotations("a^b").point(), 1u);
+  EXPECT_EQ(llvm::Annotations("ab^").point(), 2u);
+
+  // Multiple points.
+  EXPECT_THAT(llvm::Annotations("^a^bc^d^").points(),
+              ElementsAre(0u, 1u, 3u, 4u));
+
+  // No points.
+  EXPECT_THAT(llvm::Annotations("ab[[cd]]").points(), IsEmpty());
+
+  // Consecutive points.
+  EXPECT_THAT(llvm::Annotations("ab^^^cd").points(), ElementsAre(2u, 2u, 2u));
+}
+
+TEST(AnnotationsTest, Ranges) {
+  // A single range.
+  EXPECT_EQ(llvm::Annotations("[[a]]bc").range(), range(0, 1));
+  EXPECT_EQ(llvm::Annotations("a[[bc]]d").range(), range(1, 3));
+  EXPECT_EQ(llvm::Annotations("ab[[cd]]").range(), range(2, 4));
+
+  // Empty range.
+  EXPECT_EQ(llvm::Annotations("[[]]ab").range(), range(0, 0));
+  EXPECT_EQ(llvm::Annotations("a[[]]b").range(), range(1, 1));
+  EXPECT_EQ(llvm::Annotations("ab[[]]").range(), range(2, 2));
+
+  // Multiple ranges.
+  EXPECT_THAT(llvm::Annotations("[[a]][[b]]cd[[ef]]ef").ranges(),
+              ElementsAre(range(0, 1), range(1, 2), range(4, 6)));
+
+  // No ranges.
+  EXPECT_THAT(llvm::Annotations("ab^c^defef").ranges(), IsEmpty());
+}
+
+TEST(AnnotationsTest, Nested) {
+  llvm::Annotations Annotated("a[[f^oo^bar[[b[[a]]z]]]]bcdef");
+  EXPECT_THAT(Annotated.points(), ElementsAre(2u, 4u));
+  EXPECT_THAT(Annotated.ranges(),
+              ElementsAre(range(8, 9), range(7, 10), range(1, 10)));
+}
+
+TEST(AnnotationsTest, Named) {
+  // A single named point or range.
+  EXPECT_EQ(llvm::Annotations("a$foo^b").point("foo"), 1u);
+  EXPECT_EQ(llvm::Annotations("a$foo[[b]]cdef").range("foo"), range(1, 2));
+
+  // Empty names should also work.
+  EXPECT_EQ(llvm::Annotations("a$^b").point(""), 1u);
+  EXPECT_EQ(llvm::Annotations("a$[[b]]cdef").range(""), range(1, 2));
+
+  // Multiple named points.
+  llvm::Annotations Annotated("a$p1^bcd$p2^123$p1^345");
+  EXPECT_THAT(Annotated.points(), IsEmpty());
+  EXPECT_THAT(Annotated.points("p1"), ElementsAre(1u, 7u));
+  EXPECT_EQ(Annotated.point("p2"), 4u);
+}
+
+TEST(AnnotationsTest, Errors) {
+  // Annotations use llvm_unreachable, it will only crash in debug mode.
+#ifndef NDEBUG
+  // point() and range() crash on zero or multiple ranges.
+  EXPECT_DEATH(llvm::Annotations("ab[[c]]def").point(),
+               "expected exactly one point");
+  EXPECT_DEATH(llvm::Annotations("a^b^cdef").point(),
+               "expected exactly one point");
+
+  EXPECT_DEATH(llvm::Annotations("a^bcdef").range(),
+               "expected exactly one range");
+  EXPECT_DEATH(llvm::Annotations("a[[b]]c[[d]]ef").range(),
+               "expected exactly one range");
+
+  EXPECT_DEATH(llvm::Annotations("$foo^a$foo^a").point("foo"),
+               "expected exactly one point");
+  EXPECT_DEATH(llvm::Annotations("$foo[[a]]bc$foo[[a]]").range("foo"),
+               "expected exactly one range");
+
+  // Parsing failures.
+  EXPECT_DEATH(llvm::Annotations("ff[[fdfd"), "unmatched \\[\\[");
+  EXPECT_DEATH(llvm::Annotations("ff[[fdjsfjd]]xxx]]"), "unmatched ]]");
+  EXPECT_DEATH(llvm::Annotations("ff$fdsfd"), "unterminated \\$name");
+#endif
+}
+} // namespace