如何将Node.js库转换到Deno

- import * as crypto from "crypto";
+ import * as crypto from "https://deno.land/std@0.114.0/node/crypto.ts";

// adapter.node.ts
import * as path from "path";
import * as util from "util";
import * as crypto from "crypto";

export {path, net, crypto};

// adapter.deno.ts
import * as crypto from "https://deno.land/std@0.114.0/node/crypto.ts";
import path from "https://deno.land/std@0.114.0/node/path.ts";
import util from "https://deno.land/std@0.114.0/node/util.ts";

export {path, util, crypto};

import {walk} from "https://deno.land/std@0.114.0/fs/mod.ts";

const sourceDir = "./src";
for await (const entry of walk(sourceDir, {includeDirs: false})) {
  // 遍历源文件
}

const sourceDir = "./src";
const destDir = "./edgedb-deno";
const pathRewriteRules = [
  {match: /^src\/index.node.ts$/, replace: "mod.ts"},
  {match: /^src\//, replace: "_src/"},
];

const sourceFilePathMap = new Map<string, string>();

for await (const entry of walk(sourceDir, {includeDirs: false})) {
  const sourcePath = entry.path;
  sourceFilePathMap.set(sourcePath, resolveDestPath(sourcePath));
}

function resolveDestPath(sourcePath: string) {
  let destPath = sourcePath;
  // 使用重写规则
  for (const rule of pathRewriteRules) {
    destPath = destPath.replace(rule.match, rule.replace);
  }
  return join(destDir, destPath);
}

import {createRequire} from "https://deno.land/std@0.114.0/node/module.ts";

const require = createRequire(import.meta.url);
const ts = require("typescript");

import {walk, ensureDir} from "https://deno.land/std@0.114.0/fs/mod.ts";
import {createRequire} from "https://deno.land/std@0.114.0/node/module.ts";

const require = createRequire(import.meta.url);
const ts = require("typescript");

for (const [sourcePath, destPath] of sourceFilePathMap) {
  compileFileForDeno(sourcePath, destPath);
}

async function compileFileForDeno(sourcePath: string, destPath: string) {
  const file = await Deno.readTextFile(sourcePath);
  await ensureDir(dirname(destPath));

  // 如果文件以'.deno.ts'结尾则直接复制无需修改
  if (destPath.endsWith(".deno.ts")) return Deno.writeTextFile(destPath, file);
  // 如果文件以`.node.ts`结尾则跳过
  if (destPath.endsWith(".node.ts")) return;

  // 使用typescript Compiler API解析源文件
  const parsedSource = ts.createSourceFile(
    basename(sourcePath),
    file,
    ts.ScriptTarget.Latest,
    false,
    ts.ScriptKind.TS
  );
}

const parsedSource = ts.createSourceFile(/*...*/);

const rewrittenFile: string[] = [];
let cursor = 0;
parsedSource.forEachChild((node: any) => {
  if (
    (node.kind === ts.SyntaxKind.ImportDeclaration ||
      node.kind === ts.SyntaxKind.ExportDeclaration) &&
    node.moduleSpecifier
  ) {
    const pos = node.moduleSpecifier.pos + 2;
    const end = node.moduleSpecifier.end - 1;
    const importPath = file.slice(pos, end);

    rewrittenFile.push(file.slice(cursor, pos));
    cursor = end;

    // 使用Deno版本的导入替换导入适配文件
    let resolvedImportPath = resolveImportPath(importPath, sourcePath);
    if (resolvedImportPath.endsWith("/adapter.node.ts")) {
      resolvedImportPath = resolvedImportPath.replace(
        "/adapter.node.ts",
        "/adapter.deno.ts"
      );
    }

    rewrittenFile.push(resolvedImportPath);
  }
});

rewrittenFile.push(file.slice(cursor));

// global.deno.ts
export {Buffer} from "https://deno.land/std@0.114.0/node/buffer.ts";
export {process} from "https://deno.land/std@0.114.0/node/process.ts";

const sourceDir = "./src";
const destDir = "./edgedb-deno";
const pathRewriteRules = [
  {match: /^src\/index.node.ts$/, replace: "mod.ts"},
  {match: /^src\//, replace: "_src/"},
];
const injectImports = {
  imports: ["Buffer", "process"],
  from: "src/globals.deno.ts",
};

// ...

const rewrittenFile: string[] = [];
let cursor = 0;
let isFirstNode = true;
parsedSource.forEachChild((node: any) => {
  if (isFirstNode) {  // 每个文件只执行一次
    isFirstNode = false;

    const neededImports = injectImports.imports.filter((importName) =>
      parsedSource.identifiers?.has(importName)
    );

    if (neededImports.length) {
      const imports = neededImports.join(", ");
      const importPath = resolveImportPath(
        relative(dirname(sourcePath), injectImports.from),
        sourcePath
      );
      const importDecl = `import {${imports}} from "${importPath}";\n\n`;

      const injectPos = node.getLeadingTriviaWidth?.(parsedSource) ?? node.pos;
      rewrittenFile.push(file.slice(cursor, injectPos));
      rewrittenFile.push(importDecl);
      cursor = injectPos;
    }
  }

try {
  await Deno.remove(destDir, {recursive: true});
} catch {}

const sourceFilePathMap = new Map<string, string>();
for (const [sourcePath, destPath] of sourceFilePathMap) {
  // 重写文件
  await Deno.writeTextFile(destPath, rewrittenFile.join(""));
}

# .github/workflows/deno-release.yml
name: Deno Release
on:
  push:
    branches:
      - master
jobs:
  release:
    runs-on: ubuntu-latest
    steps:
      - name: Checkout edgedb-js
        uses: actions/checkout@v2
      - name: Checkout edgedb-deno
        uses: actions/checkout@v2
        with:
          token: ${{ secrets.GITHUB_TOKEN }}
          repository: edgedb/edgedb-deno
          path: edgedb-deno
      - uses: actions/setup-node@v2
      - uses: denoland/setup-deno@v1
      - name: Install deps
        run: yarn install
      - name: Get version from package.json
        id: package-version
        uses: martinbeentjes/npm-get-version-action@v1.1.0
      - name: Write version to file
        run: echo "${{ steps.package-version.outputs.current-version}}" > edgedb-deno/version.txt
      - name: Compile for Deno
        run: deno run --unstable --allow-env --allow-read --allow-write tools/compileForDeno.ts
      - name: Push to edgedb-deno
        run: cd edgedb-deno && git add . -f && git commit -m "Build from $GITHUB_SHA" && git push