如何使用打字稿编译器 API 获取正常的函数信息，例如:返回类型/参数

Question

/**
 * class of User
 */
class User {
    /**
     * constructor
     * @param name c-name
     */
    constructor(name: string) {
        this.name = name
    }
    /**
     * property name
     */
    private name: string
    /**
     * setName
     * @param name f-name
     */
    public setName(name: string) {
        this.name = name
    }
}

我看到了打字稿 Wiki，我可以获取构造函数的信息，例如：返回类型/参数。

[
    {
        "name": "User",
        "documentation": "class of User",
        "type": "typeof User",
        "constructors": [
            {
                "parameters": [
                    {
                        "name": "name",
                        "documentation": "c-name",
                        "type": "string"
                    }
                ],
                "returnType": "User",
                "documentation": "constructor"
            }
        ]
    }
]

但是我想在普通函数getName上获取返回类型/参数/文档的信息，我该怎么做？

ps：I知道构造函数有签名，签名有函数getReturntype，但普通函数没有签名，所以我无法获取信息

谢谢！

Answer 1

假设您知道如何获取MethodDeclaration，那么以下内容将起作用：

// I'm assuming you know how to get the type checker from the compiler too.
const typeChecker = ...;
// Navigate through the tree to get to the method declaration located in the class.
// This is the node with kind === ts.SyntaxKind.MethodDeclaration or
// you can use ts.isMethodDeclaration(node)
const methodDeclaration = ... as ts.MethodDeclaration;
const signature = typeChecker.getSignatureFromDeclaration(methodDeclaration);
const returnType = typeChecker.getReturnTypeOfSignature(signature);
const parameters = methodDeclaration.parameters; // array of Parameters
const docs = methodDeclaration.jsDoc; // array of js docs

顺便说一下，你应该看看我写的这个AST查看器。它可能会帮助您解决将来遇到的一些问题。此外，根据您的用例，ts-morph 将有助于使导航和操作 AST 更容易一些。