[clang-tools-extra] [clang-doc] Add Markdown AST node type definitions (PR #205609)

[Neil Nair via cfe-commits]

================
@@ -0,0 +1,94 @@
+//===----------------------------------------------------------------------===//
+//
+// 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 "support/Markdown.h"
+#include "gtest/gtest.h"
+
+using namespace clang::doc::markdown;
+using namespace llvm;
+
+namespace {
+
+TEST(MarkdownNodeTest, TextNode) {
+  TextNode N("hello");
+  EXPECT_EQ(N.Kind, NodeKind::NK_Text);
+  EXPECT_EQ(N.getText(), "hello");
+}
+
+TEST(MarkdownNodeTest, FencedCodeNode) {
+  FencedCodeNode N("cpp", "int x = 0;\nint y = 1;");
+  EXPECT_EQ(N.Kind, NodeKind::NK_FencedCode);
+  EXPECT_EQ(N.getLang(), "cpp");
+  EXPECT_TRUE(N.getCode().contains("int x = 0;"));
+  EXPECT_TRUE(N.getCode().contains("int y = 1;"));
+}
+
+TEST(MarkdownNodeTest, HeadingNode) {
+  HeadingNode N(2);
+  EXPECT_EQ(N.Kind, NodeKind::NK_Heading);
+  EXPECT_EQ(N.getLevel(), 2u);
+}
+
+TEST(MarkdownNodeTest, ThematicBreakNode) {
+  ThematicBreakNode N;
+  EXPECT_EQ(N.Kind, NodeKind::NK_ThematicBreak);
+}
+
+TEST(MarkdownNodeTest, InlineCodeNode) {
+  InlineCodeNode N("foo()");
+  EXPECT_EQ(N.Kind, NodeKind::NK_InlineCode);
+  EXPECT_EQ(N.getCode(), "foo()");
+}
+
+TEST(MarkdownNodeTest, EmphasisNode) {
+  EmphasisNode N;
+  TextNode Child("emphasized");
+  N.Children.push_back(Child);
+  EXPECT_EQ(N.Kind, NodeKind::NK_Emphasis);
+  EXPECT_FALSE(N.Children.empty());
+  EXPECT_EQ(llvm::cast<TextNode>(N.Children.front()).getText(), "emphasized");
----------------
Neil-N4 wrote:

Added a firstChildText() helper to reduce the repeated cast pattern

https://github.com/llvm/llvm-project/pull/205609