[clang-doc] Add basic e2e test (#93928)

Adds e2e tests for clang-doc, which serves as useful test against
regression in the html output. It also serves as a helpful tool for code
review as we can see the diffs to clang-docs output

Closes #93925

Author: PeterChou1

clang-tools-extra/clang-doc/tool/ClangDocMain.cpp

@@ -299,8 +299,7 @@ Example usage for a project using a compile commands database:
   llvm::outs() << "Generating assets for docs...\n";
   Err = G->get()->createResources(CDCtx);
   if (Err) {
-    llvm::errs() << toString(std::move(Err)) << "\n";
-    return 1;
+    llvm::outs() << "warning: " << toString(std::move(Err)) << "\n";
   }
 
   return 0;

clang-tools-extra/test/clang-doc/Inputs/basic-project/database_template.json

@@ -0,0 +1,17 @@
+[
+  {
+    "directory": "$test_dir/Inputs/basic-project",
+    "command": "clang++ -o Calculator.o -I./include ./src/Calculator.cpp",
+    "file": "./src/Calculator.cpp"
+  },
+  {
+    "directory": "$test_dir/Inputs/basic-project",
+    "command": "clang++ -o Circle.o -I./include ./src/Circle.cpp",
+    "file": "./src/Circle.cpp"
+  },
+  {
+    "directory": "$test_dir/Inputs/basic-project",
+    "command": "clang++ -o Rectangle.o -I./include ./src/Rectangle.cpp",
+    "file": "./src/Rectangle.cpp"
+  }
+]

clang-tools-extra/test/clang-doc/Inputs/basic-project/include/Calculator.h

@@ -0,0 +1,46 @@
+#pragma once
+
+/**
+ * @brief A simple calculator class.
+ *
+ * Provides basic arithmetic operations.
+ */
+class Calculator {
+public:
+    /**
+     * @brief Adds two integers.
+     *
+     * @param a First integer.
+     * @param b Second integer.
+     * @return int The sum of a and b.
+     */
+    int add(int a, int b);
+
+    /**
+     * @brief Subtracts the second integer from the first.
+     *
+     * @param a First integer.
+     * @param b Second integer.
+     * @return int The result of a - b.
+     */
+    int subtract(int a, int b);
+
+    /**
+     * @brief Multiplies two integers.
+     *
+     * @param a First integer.
+     * @param b Second integer.
+     * @return int The product of a and b.
+     */
+    int multiply(int a, int b);
+
+    /**
+     * @brief Divides the first integer by the second.
+     *
+     * @param a First integer.
+     * @param b Second integer.
+     * @return double The result of a / b.
+     * @throw std::invalid_argument if b is zero.
+     */
+    double divide(int a, int b);
+};

clang-tools-extra/test/clang-doc/Inputs/basic-project/include/Circle.h

@@ -0,0 +1,35 @@
+#pragma once
+
+#include "Shape.h"
+
+/**
+ * @brief Circle class derived from Shape.
+ *
+ * Represents a circle with a given radius.
+ */
+class Circle : public Shape {
+public:
+    /**
+     * @brief Constructs a new Circle object.
+     *
+     * @param radius Radius of the circle.
+     */
+    Circle(double radius);
+
+    /**
+     * @brief Calculates the area of the circle.
+     *
+     * @return double The area of the circle.
+     */
+    double area() const override;
+
+    /**
+     * @brief Calculates the perimeter of the circle.
+     *
+     * @return double The perimeter of the circle.
+     */
+    double perimeter() const override;
+
+private:
+    double radius_; ///< Radius of the circle.
+};

clang-tools-extra/test/clang-doc/Inputs/basic-project/include/Rectangle.h

@@ -0,0 +1,37 @@
+#pragma once
+
+#include "Shape.h"
+
+/**
+ * @brief Rectangle class derived from Shape.
+ *
+ * Represents a rectangle with a given width and height.
+ */
+class Rectangle : public Shape {
+public:
+    /**
+     * @brief Constructs a new Rectangle object.
+     *
+     * @param width Width of the rectangle.
+     * @param height Height of the rectangle.
+     */
+    Rectangle(double width, double height);
+
+    /**
+     * @brief Calculates the area of the rectangle.
+     *
+     * @return double The area of the rectangle.
+     */
+    double area() const override;
+
+    /**
+     * @brief Calculates the perimeter of the rectangle.
+     *
+     * @return double The perimeter of the rectangle.
+     */
+    double perimeter() const override;
+
+private:
+    double width_; ///< Width of the rectangle.
+    double height_; ///< Height of the rectangle.
+};

clang-tools-extra/test/clang-doc/Inputs/basic-project/include/Shape.h

@@ -0,0 +1,30 @@
+#pragma once
+
+/**
+ * @brief Abstract base class for shapes.
+ *
+ * Provides a common interface for different types of shapes.
+ */
+class Shape {
+public:
+    /**
+     * @brief Virtual destructor.
+     */
+    virtual ~Shape() {}
+
+    /**
+     * @brief Calculates the area of the shape.
+     *
+     * @return double The area of the shape.
+     */
+    virtual double area() const = 0;
+
+    /**
+     * @brief Calculates the perimeter of the shape.
+     *
+     * @return double The perimeter of the shape.
+     */
+    virtual double perimeter() const = 0;
+};
+
+

clang-tools-extra/test/clang-doc/Inputs/basic-project/src/Calculator.cpp

@@ -0,0 +1,21 @@
+#include "Calculator.h"
+#include <stdexcept>
+
+int Calculator::add(int a, int b) {
+    return a + b;
+}
+
+int Calculator::subtract(int a, int b) {
+    return a - b;
+}
+
+int Calculator::multiply(int a, int b) {
+    return a * b;
+}
+
+double Calculator::divide(int a, int b) {
+    if (b == 0) {
+        throw std::invalid_argument("Division by zero");
+    }
+    return static_cast<double>(a) / b;
+}

clang-tools-extra/test/clang-doc/Inputs/basic-project/src/Circle.cpp

@@ -0,0 +1,11 @@
+#include "Circle.h"
+
+Circle::Circle(double radius) : radius_(radius) {}
+
+double Circle::area() const {
+    return 3.141 * radius_ * radius_;
+}
+
+double Circle::perimeter() const {
+    return 3.141 * radius_;
+}

clang-tools-extra/test/clang-doc/Inputs/basic-project/src/Rectangle.cpp

@@ -0,0 +1,12 @@
+#include "Rectangle.h"
+
+Rectangle::Rectangle(double width, double height)
+        : width_(width), height_(height) {}
+
+double Rectangle::area() const {
+    return width_ * height_;
+}
+
+double Rectangle::perimeter() const {
+    return 2 * (width_ + height_);
+}