neon-cli/src/crate.ts

Build and load native Rust/Neon modules.

import TOML from "toml";
import path from "path";
import { readFileSync, promises as fs } from "fs";
import Artifacts from "./artifacts";
import Project from "./project";
import { rimraf } from "./async/rimraf";

export type CrateOptions = {
  subdirectory?: string;
  nodefile?: string;
};

// Represents the native crate inside a Neon project.
export default class Crate {
  /** The Neon project containing this crate. */
  readonly project: Project;
  /** The subpath of this crate relative to the Neon project root. */
  readonly subdirectory: string;
  /** The subpath of the `.node` addon relative to this crate root. */
  readonly nodefile: string;
  /** The absolute path of this crate. */
  readonly root: string;
  /** The absolute path of the `.node` addon. */
  readonly addon: string;
  /** The crate name extracted from the manifest. */
  readonly name: string;
  /** The absolute path of the artifacts file. */
  readonly artifactsfile: string;
  /** The state of current build artifacts for each target. */
  readonly artifacts: Artifacts;

  constructor(project: Project, options: CrateOptions = {}) {
    let { subdirectory = "native", nodefile = "index.node" } = options;
    this.project = project;
    this.subdirectory = subdirectory;
    this.nodefile = nodefile;
    this.root = path.resolve(project.root, subdirectory);
    this.addon = path.resolve(this.root, nodefile);
    this.name = loadLibName(path.resolve(this.root, "Cargo.toml"));
    this.artifactsfile = path.resolve(this.root, "artifacts.json");
    this.artifacts = Artifacts.load(this.artifactsfile);
  }

  async finish(dylib: string) {
    await rimraf(this.addon);
    await fs.copyFile(dylib, this.addon);
  }

  async removeAddon() {
    await rimraf(this.addon);
  }

  resetArtifacts() {
    this.artifacts.reset();
  }

  saveArtifacts() {
    this.artifacts.save(this.artifactsfile);
  }
}

type Metadata = {
  lib?: {
    name?: string;
  };
};

function loadLibName(file: string): string {
  let metadata = TOML.parse<Metadata>(readFileSync(file, "utf8"));
  if (!metadata) throw new Error(`Failed to parse TOML file "${file}"`);

  if (!metadata || typeof metadata !== "object" || !metadata?.lib?.name) {
    throw new Error(
      "Cargo.toml does not contain a [lib] section with a 'name' field"
    );
  }

  return metadata.lib.name;
}