使用 `Roslyn` 分析器和修复器对.cs源代码添加头部注释
之前写过两篇关于Roslyn源生成器生成源代码的用例,今天使用Roslyn的代码修复器CodeFixProvider实现一个cs文件头部注释的功能,
代码修复器会同时涉及到CodeFixProvider和DiagnosticAnalyzer,
实现FileHeaderAnalyzer
首先我们知道修复器的先决条件是分析器,比如这里,如果要对代码添加头部注释,那么分析器必须要给出对应的分析提醒:
我们首先实现实现名为FileHeaderAnalyzer的分析器:
[DiagnosticAnalyzer(LanguageNames.CSharp)]
public class FileHeaderAnalyzer : DiagnosticAnalyzer
{
public const string DiagnosticId = "GEN050";
private static readonly LocalizableString Title = "文件缺少头部信息";
private static readonly LocalizableString MessageFormat = "文件缺少头部信息";
private static readonly LocalizableString Description = "每个文件应包含头部信息.";
private const string Category = "Document";
private static readonly DiagnosticDescriptor Rule = new(
DiagnosticId, Title, MessageFormat, Category, DiagnosticSeverity.Warning, isEnabledByDefault: true, description: Description);
public override ImmutableArray<DiagnosticDescriptor> SupportedDiagnostics => [Rule];
public override void Initialize(AnalysisContext context)
{
if (context is null)
return;
context.ConfigureGeneratedCodeAnalysis(GeneratedCodeAnalysisFlags.None);
context.EnableConcurrentExecution();
context.RegisterSyntaxTreeAction(AnalyzeSyntaxTree);
}
private static void AnalyzeSyntaxTree(SyntaxTreeAnalysisContext context)
{
var root = context.Tree.GetRoot(context.CancellationToken);
var firstToken = root.GetFirstToken();
// 检查文件是否以注释开头
var hasHeaderComment = firstToken.LeadingTrivia.Any(trivia => trivia.IsKind(SyntaxKind.SingleLineCommentTrivia) || trivia.IsKind(SyntaxKind.MultiLineCommentTrivia));
if (!hasHeaderComment)
{
var diagnostic = Diagnostic.Create(Rule, Location.Create(context.Tree, TextSpan.FromBounds(0, 0)));
context.ReportDiagnostic(diagnostic);
}
}
}
FileHeaderAnalyzer分析器的原理很简单,需要重载几个方法,重点是Initialize方法,这里的RegisterSyntaxTreeAction即核心代码,SyntaxTreeAnalysisContext对象取到当前源代码的SyntaxNode根节点,然后判断TA的第一个SyntaxToken是否为注释行(SyntaxKind.SingleLineCommentTrivia|SyntaxKind.MultiLineCommentTrivia)
如果不为注释行,那么就通知分析器!
实现了上面的代码我们看一下效果:
并且编译的时候分析器将会在错误面板中显示警告清单:
实现CodeFixProvider
分析器完成了,现在我们就来实现名为AddFileHeaderCodeFixProvider的修复器,
/// <summary>
/// 自动给文件添加头部注释
/// </summary>
[ExportCodeFixProvider(LanguageNames.CSharp, Name = nameof(AddFileHeaderCodeFixProvider))]
[Shared]
public class AddFileHeaderCodeFixProvider : CodeFixProvider
{
private const string Title = "添加文件头部信息";
//约定模板文件的名称
private const string ConfigFileName = "Biwen.AutoClassGen.Comment";
private const string VarPrefix = "$";//变量前缀
//如果模板不存在的时候的默认注释文本
private const string DefaultComment = """
// Licensed to the {Product} under one or more agreements.
// The {Product} licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.
""";
#region regex
private const RegexOptions ROptions = RegexOptions.Compiled | RegexOptions.Singleline;
private static readonly Regex VersionRegex = new(@"<Version>(.*?)</Version>", ROptions);
private static readonly Regex CopyrightRegex = new(@"<Copyright>(.*?)</Copyright>", ROptions);
private static readonly Regex CompanyRegex = new(@"<Company>(.*?)</Company>", ROptions);
private static readonly Regex DescriptionRegex = new(@"<Description>(.*?)</Description>", ROptions);
private static readonly Regex AuthorsRegex = new(@"<Authors>(.*?)</Authors>", ROptions);
private static readonly Regex ProductRegex = new(@"<Product>(.*?)</Product>", ROptions);
private static readonly Regex TargetFrameworkRegex = new(@"<TargetFramework>(.*?)</TargetFramework>", ROptions);
private static readonly Regex TargetFrameworksRegex = new(@"<TargetFrameworks>(.*?)</TargetFrameworks>", ROptions);
private static readonly Regex ImportRegex = new(@"<Import Project=""(.*?)""", ROptions);
#endregion
public sealed override ImmutableArray<string> FixableDiagnosticIds
{
//重写FixableDiagnosticIds,返回分析器的报告Id,表示当前修复器能修复的对应Id
get { return [FileHeaderAnalyzer.DiagnosticId]; }
}
public sealed override FixAllProvider GetFixAllProvider()
{
return WellKnownFixAllProviders.BatchFixer;
}
public override Task RegisterCodeFixesAsync(CodeFixContext context)
{
var diagnostic = context.Diagnostics[0];
var diagnosticSpan = diagnostic.Location.SourceSpan;
context.RegisterCodeFix(
CodeAction.Create(
title: Title,
createChangedDocument: c => FixDocumentAsync(context.Document, diagnosticSpan, c),
equivalenceKey: Title),
diagnostic);
return Task.CompletedTask;
}
private static async Task<Document> FixDocumentAsync(Document document, TextSpan span, CancellationToken ct)
{
var root = await document.GetSyntaxRootAsync(ct).ConfigureAwait(false);
//从项目配置中获取文件头部信息
var projFilePath = document.Project.FilePath ?? "C:\\test.csproj";//单元测试时没有文件路径,因此使用默认路径
var projectDirectory = Path.GetDirectoryName(projFilePath);
var configFilePath = Path.Combine(projectDirectory, ConfigFileName);
var comment = DefaultComment;
string? copyright = "MIT";
string? author = Environment.UserName;
string? company = string.Empty;
string? description = string.Empty;
string? title = document.Project.Name;
string? version = document.Project.Version.ToString();
string? product = document.Project.AssemblyName;
string? file = Path.GetFileName(document.FilePath);
string? targetFramework = string.Empty;
#pragma warning disable CA1305 // 指定 IFormatProvider
string? date = DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss");
#pragma warning restore CA1305 // 指定 IFormatProvider
if (File.Exists(configFilePath))
{
comment = File.ReadAllText(configFilePath, System.Text.Encoding.UTF8);
}
#region 查找程序集元数据
// 加载项目文件:
var text = File.ReadAllText(projFilePath, System.Text.Encoding.UTF8);
// 载入Import的文件,例如 : <Import Project="..\Version.props" />
// 使用正则表达式匹配Project:
var importMatchs = ImportRegex.Matches(text);
foreach (Match importMatch in importMatchs)
{
var importFile = Path.Combine(projectDirectory, importMatch.Groups[1].Value);
if (File.Exists(importFile))
{
text += File.ReadAllText(importFile);
}
}
//存在变量引用的情况,需要解析
string RawVal(string old, string @default)
{
if (old == null)
return @default;
//当取得的版本号为变量引用:$(Version)的时候,需要再次解析
if (version.StartsWith(VarPrefix, StringComparison.Ordinal))
{
var varName = old.Substring(2, old.Length - 3);
var varMatch = new Regex($@"<{varName}>(.*?)</{varName}>", RegexOptions.Singleline).Match(text);
if (varMatch.Success)
{
return varMatch.Groups[1].Value;
}
//未找到变量引用,返回默
return @default;
}
return old;
}
var versionMatch = VersionRegex.Match(text);
var copyrightMath = CopyrightRegex.Match(text);
var companyMatch = CompanyRegex.Match(text);
var descriptionMatch = DescriptionRegex.Match(text);
var authorsMatch = AuthorsRegex.Match(text);
var productMatch = ProductRegex.Match(text);
var targetFrameworkMatch = TargetFrameworkRegex.Match(text);
var targetFrameworksMatch = TargetFrameworksRegex.Match(text);
if (versionMatch.Success)
{
version = RawVal(versionMatch.Groups[1].Value, version);
}
if (copyrightMath.Success)
{
copyright = RawVal(copyrightMath.Groups[1].Value, copyright);
}
if (companyMatch.Success)
{
company = RawVal(companyMatch.Groups[1].Value, company);
}
if (descriptionMatch.Success)
{
description = RawVal(descriptionMatch.Groups[1].Value, description);
}
if (authorsMatch.Success)
{
author = RawVal(authorsMatch.Groups[1].Value, author);
}
if (productMatch.Success)
{
product = RawVal(productMatch.Groups[1].Value, product);
}
if (targetFrameworkMatch.Success)
{
targetFramework = RawVal(targetFrameworkMatch.Groups[1].Value, targetFramework);
}
if (targetFrameworksMatch.Success)
{
targetFramework = RawVal(targetFrameworksMatch.Groups[1].Value, targetFramework);
}
#endregion
//使用正则表达式替换
comment = Regex.Replace(comment, @"\{(?<key>[^}]+)\}", m =>
{
var key = m.Groups["key"].Value;
return key switch
{
"Product" => product,
"Title" => title,
"Version" => version,
"Date" => date,
"Author" => author,
"Company" => company,
"Copyright" => copyright,
"File" => file,
"Description" => description,
"TargetFramework" => targetFramework,
_ => m.Value,
};
}, RegexOptions.Singleline);
var headerComment = SyntaxFactory.Comment(comment + Environment.NewLine);
var newRoot = root?.WithLeadingTrivia(headerComment);
if (newRoot == null)
{
return document;
}
var newDocument = document.WithSyntaxRoot(newRoot);
return newDocument;
}
}
代码修复器最重要的重载方法RegisterCodeFixesAsync,对象CodeFixContext包含项目和源代码以及对应分析器的信息:
比如:CodeFixContext.Document表示对应的源代码,CodeFixContext.Document.Project表示对应项目,CodeFixContext.Document.Project.FilePath就是代码中我需要的*.csproj的项目文件,
我们取到项目文件,那么我们就可以读取配置在项目文件中的信息,比如Company,Authors,Description,甚至上一篇我们提到的版本号等有用信息,当前我用的正则表达式,当然如果可以你也可以使用XPath,
然后取到的有用数据替换模板即可得到想要的注释代码片段了!
比如我的Comment模板文件Biwen.AutoClassGen.Comment
// Licensed to the {Product} under one or more agreements.
// The {Product} licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.
// {Product} Author: {Author} Github: https://github.com/vipwan
// {Description}
// Modify Date: {Date} {File}
替换后将会生成如下的代码:
// Licensed to the Biwen.QuickApi under one or more agreements.
// The Biwen.QuickApi licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.
// Biwen.QuickApi Author: 万雅虎 Github: https://github.com/vipwan
// Biwen.QuickApi ,NET9+ MinimalApi CQRS
// Modify Date: 2024-09-07 15:22:42 Verb.cs
最后使用SyntaxFactory.Comment(comment)方法生成一个注释的SyntaxTrivia并附加到当前的根语法树上,最后返回这个新的Document即可!
大功告成,我们来看效果:
以上代码就完成了整个代码修复器步骤,最后你可以使用我发布的nuget包体验:
dotnet add package Biwen.AutoClassGen
源代码我发布到了GitHub,欢迎star! https://github.com/vipwan/Biwen.AutoClassGen
