Merge pull request #90 from oscarotero/master

Added support for npm

Author: hayd

registry.ts

@@ -145,6 +145,62 @@ export class DenoLand implements RegistryUrl {
   regexp = /https?:\/\/deno.land\/(?:std\@[^\'\"]*|x\/[^\/\"\']*?\@[^\'\"]*)/;
 }
 
+const NPM_CACHE: Map<string, string[]> = new Map<string, string[]>();
+export class Npm implements RegistryUrl {
+  url: string;
+  parseRegex = /^npm:(\@[^/]+\/[^@/]+|[^@/]+)(?:\@([^/]+))?(.*)/;
+
+  constructor(url: string) {
+    this.url = url;
+  }
+
+  name(): string {
+    const [, name] = this.url.match(this.parseRegex)!;
+
+    return name;
+  }
+
+  async all(): Promise<string[]> {
+    const name = this.name();
+    if (NPM_CACHE.has(name)) {
+      return NPM_CACHE.get(name)!;
+    }
+
+    try {
+      const json: VersionsJson =
+        await (await fetch(`https://registry.npmjs.org/${name}`))
+          .json();
+      if (!json.versions) {
+        throw new Error(`versions.json for ${name} has incorrect format`);
+      }
+
+      const versions = Object.keys(json.versions).reverse();
+      NPM_CACHE.set(name, versions);
+      return versions;
+    } catch (err) {
+      // TODO this could be a permissions error e.g. no --allow-net...
+      console.error(`error getting versions for ${name}`);
+      throw err;
+    }
+  }
+
+  at(version: string): RegistryUrl {
+    const [, name, _, files] = this.url.match(this.parseRegex)!;
+    const url = `npm:${name}@${version}${files}`;
+    return new Npm(url);
+  }
+
+  version(): string {
+    const [, _, version] = this.url.match(this.parseRegex)!;
+    if (version === null) {
+      throw Error(`Unable to find version in ${this.url}`);
+    }
+    return version;
+  }
+
+  regexp = /npm:(\@[^/]+\/[^@/]+|[^@/]+)(?:\@([^/]+))?[^\'\"]/;
+}
+
 async function unpkgVersions(name: string): Promise<string[]> {
   const page = await fetch(`https://unpkg.com/browse/${name}/`);
   const text = await page.text();
@@ -710,4 +766,5 @@ export const REGISTRIES = [
   GitlabRaw,
   JsDelivr,
   NestLand,
+  Npm,
 ];

registry_test.ts

@@ -170,3 +170,21 @@ Deno.test("registryNestLand", () => {
   const vAt = v.at("0.2.0");
   assertEquals(vAt.url, "https://x.nest.land/foo@0.2.0/foo.ts");
 });
+
+Deno.test("registryNpm", () => {
+  const url = "npm:foo@0.1.0/foo";
+  const v = lookup(url, REGISTRIES);
+  assert(v !== undefined);
+
+  const vAt = v.at("0.2.0");
+  assertEquals(vAt.url, "npm:foo@0.2.0/foo");
+});
+
+Deno.test("registryNpmOrg", () => {
+  const url = "npm:@foo/foo@0.1.0/foo";
+  const v = lookup(url, REGISTRIES);
+  assert(v !== undefined);
+
+  const vAt = v.at("0.2.0");
+  assertEquals(vAt.url, "npm:@foo/foo@0.2.0/foo");
+});