List typescript deprecations

README.md

List deprecations

This script will extract deprecations using the TypeScript API.

It's not 100% reliable, but it's pretty good. There seems to be an issue where overloaded functions that have a single deprecated clause will aways report.

typescript-declarations.js

#!/usr/bin/env node

import { createRequire } from "module";
import path from "path";

const require = createRequire(path.join(process.cwd(), "package.json"));
const ts = require("typescript");

const configPath = ts.findConfigFile("./", ts.sys.fileExists, "tsconfig.json");
if (!configPath) throw new Error("Could not find a valid 'tsconfig.json'.");

const configFile = ts.readConfigFile(configPath, ts.sys.readFile);
const parsedCommandLine = ts.parseJsonConfigFileContent(
  configFile.config,
  ts.sys,
  path.dirname(configPath),
);

const program = ts.createProgram({
  rootNames: parsedCommandLine.fileNames,
  options: parsedCommandLine.options,
});

const checker = program.getTypeChecker();

for (const sourceFile of program.getSourceFiles()) {
  if (sourceFile.isDeclarationFile) continue;

  ts.forEachChild(sourceFile, function visit(node) {
    const symbol = node.name && checker.getSymbolAtLocation(node.name);

    if (symbol) {
      const docs = symbol.getJsDocTags();
      const deprecated = docs.find((tag) => tag.name === "deprecated");

      if (deprecated) {
        const name = symbol.getName();
        const { line, character } = sourceFile.getLineAndCharacterOfPosition(
          node.getStart(),
        );
        const filename = path.relative(process.cwd(), sourceFile.fileName);
        console.log(`${name} at ${filename}:${line + 1}:${character + 1}`);
      }
    }

    ts.forEachChild(node, visit);
  });
}