Ts-morph: How to retreive the name property of a FunctionDeclaration ?

[pierregallard]

I am unable to retrieve the name property of a FunctionDeclaration.

For clarity purposes i will take a minimalistic example with this simple script : ( test.ts )

function example(){
}

As you can here, the FunctionDeclaration node has a name property : https://ts-ast-viewer.com/#code/GYVwdgxgLglg9mABAUwB4EMC2AHANsgCgEoBvAKAF8g

This pure typescript code is able to retrieve and log the name property : ( ts_comp_version.ts )

import * as ts from "typescript";
import * as fs from "fs";

function test(fileNames: string[],options: ts.CompilerOptions): void {
    function visit(node) {
        if (ts.isFunctionDeclaration(node)){
            console.log((node as ts.FunctionDeclaration).name);
        }
        node.getChildren().forEach((child) => visit(child)); //recursively visit every child
    }

    const program = ts.createProgram(fileNames, options);
    for (const sourceFile of program.getSourceFiles()){
        if (!sourceFile.isDeclarationFile){
            sourceFile.forEachChild((child) => visit(child)); //visit every child
        }
    }
}

test(process.argv.slice(2), {
    target: ts.ScriptTarget.ES5,
    module: ts.ModuleKind.CommonJS
});

_To Run the script enter tsc ts_comp_version.ts --m commonjs and then node ts_comp_version.js test.ts in cmd (with nodejs and TypeScript installed)._

But the "ts-morph equivalent" is failing to do so : ( tsm.ts )

import * as ts from "typescript";
import * as fs from "fs";
import * as tsm from "ts-morph";

function test(fileNames: string[],options: ts.CompilerOptions): void {
    function visit(node) {
        if (tsm.TypeGuards.isFunctionDeclaration(node)){ 
            console.log((node as tsm.TypeGuards.FunctionDeclaration).name)
        }
        node.getChildren().forEach((child) => visit(child)); //visit every child
    }

    const project = new tsm.Project();
    for (const fileName of fileNames){
        let sourceFile = project.addSourceFileAtPath(fileName);
        sourceFile.getChildren().forEach((child) => visit(child)); //visit every child
    }
}

test(process.argv.slice(2), {
    target: ts.ScriptTarget.ES5,
    module: ts.ModuleKind.CommonJS
});

_To Run the script enter tsc tsm.ts --m commonjs (it won't work) and then (if the issue was fixed) node tsm.js test.ts in cmd (with nodejs, TypeScript and ts-morph installed)._
error TS2694: Namespace '"C:/(...)/nodejs/node-v12.16.0-win-x64/node_modules/ts-morph/lib/ts-morph"' has no exported member 'TypeGuards'.

What I am missing here, how can I access the name property ?

I need to retrieve it in order to be able to get symbols. There is currently no documentation about ts-morph symbols ( https://ts-morph.com/details/index ) so I suppose that they are retrieved in ts-compiler fashion: const symbol = checker.getSymbolAtLocation((node as ts.FunctionDeclaration).name); ?

[dsherret]

You should be getting a compile error with that code. Those isX checks are now on Node and not TypeGuards. Use Node.isFunctionDeclaration then you can use getName.

[dsherret]

Sorry, I’ve been busy the past few days so haven’t got to your other questions. I’m also on my phone. What can be helpful is to search through the ts-morph .d.ts file for things. Ex. There is a .getSymbol() method on every node.