Switch to using git tags to compare the dts files

Author: orta

deploy/createTypesPackages.mjs

@@ -3,7 +3,7 @@
 // node deploy/createTypesPackages.mjs
 
 // prettier-ignore
-const packages = [
+export const packages = [
     {
       name: "@types/web",
       description: "Types for the DOM, and other web technologies in browsers",
@@ -71,8 +71,6 @@ const go = async () => {
   }
 };
 
-go();
-
 async function updatePackageJSON(packagePath, pkg, gitSha) {
   const pkgJSONPath = join(packagePath, "package.json");
   const packageText = fs.readFileSync(pkgJSONPath, "utf8");
@@ -131,3 +129,7 @@ function copyREADME(pkg, pkgJSON, writePath) {
 
   fs.writeFileSync(writePath, readme);
 }
+
+if (process.argv[1] === fileURLToPath(import.meta.url)) {
+  go();
+}

deploy/deployChangedPackages.mjs

@@ -6,13 +6,13 @@
 // ones which have changed.
 
 import * as fs from "fs";
-import { join, dirname } from "path";
+import { join, dirname, basename } from "path";
 import { fileURLToPath } from "url";
-import fetch from "node-fetch";
-import { spawnSync } from "child_process";
+import { spawnSync, execSync } from "child_process";
 import { Octokit } from "@octokit/core";
 import printDiff from "print-diff";
 import { generateChangelogFrom } from "../lib/changelog.js";
+import { packages } from "./createTypesPackages.mjs";
 
 // eslint-disable-next-line @typescript-eslint/ban-ts-comment
 // @ts-ignore
@@ -27,6 +27,9 @@ const verify = () => {
     );
 };
 
+const gitShowFile = (commitish, path) =>
+  execSync(`git show "${commitish}":${path}`, { encoding: "utf-8" });
+
 const go = async () => {
   verify();
 
@@ -41,6 +44,10 @@ const go = async () => {
     const newTSConfig = fs.readFileSync(localPackageJSONPath, "utf-8");
     const pkgJSON = JSON.parse(newTSConfig);
 
+    // We'll need to map back from the filename in the npm package to the
+    // generated file in baselines inside the git tag
+    const thisPackageMeta = packages.find((p) => p.name === pkgJSON.name);
+
     const dtsFiles = fs
       .readdirSync(join(generatedDir, dirName))
       .filter((f) => f.endsWith(".d.ts"));
@@ -52,25 +59,36 @@ const go = async () => {
     // determine if anything has changed
     let upload = false;
     for (const file of dtsFiles) {
+      const originalFilename = basename(
+        thisPackageMeta.files.find((f) => f.to === file).from
+      );
+
       const generatedDTSPath = join(generatedDir, dirName, file);
       const generatedDTSContent = fs.readFileSync(generatedDTSPath, "utf8");
-      const unpkgURL = `https://unpkg.com/${pkgJSON.name}/${file}`;
+
+      // This assumes we'll only _ever_ ship patches, which may change in the
+      // future someday.
+      const [maj, min, patch] = pkgJSON.version.split(".");
+      const olderVersion = `${maj}.${min}.${patch - 1}`;
+
       try {
-        const npmDTSReq = await fetch(unpkgURL);
-        const npmDTSText = await npmDTSReq.text();
-        console.log(`Comparing ${file} from unpkg, to generated version:`);
-        printDiff(npmDTSText, generatedDTSContent);
+        const oldFile = gitShowFile(
+          `${pkgJSON.name}@${olderVersion}`,
+          `baselines/${originalFilename}`
+        );
+        console.log(`Comparing ${file} from ${olderVersion}, to now:`);
+        printDiff(oldFile, generatedDTSContent);
 
         const title = `\n## \`${file}\`\n`;
-        const notes = generateChangelogFrom(npmDTSText, generatedDTSContent);
+        const notes = generateChangelogFrom(oldFile, generatedDTSContent);
         releaseNotes.push(title);
         releaseNotes.push(notes.trim() === "" ? "No changes" : notes);
 
-        upload = upload || npmDTSText !== generatedDTSContent;
+        upload = upload || oldFile !== generatedDTSContent;
       } catch (error) {
         // Could not find a previous build
         console.log(`
-Could not get the file ${file} inside the npm package ${pkgJSON.name} from unpkg at ${unpkgURL}
+Could not get the file ${file} inside the npm package ${pkgJSON.name} from tag ${olderVersion}.
 Assuming that this means we need to upload this package.`);
         upload = true;
       }

src/changelog.ts

@@ -141,7 +141,11 @@ export function generateDefaultFromRecentTag(): string {
   const [base = gitLatestTag(), head = "HEAD"] = process.argv.slice(2);
   const previous = gitShowFile(base, dom);
   const current = gitShowFile(head, dom);
-  return generateChangelogFrom(previous, current);
+  const changelog = generateChangelogFrom(previous, current);
+  if (!changelog.length) {
+    throw new Error(`No change reported between ${base} and ${head}.`);
+  }
+  return changelog;
 }
 
 export function generateChangelogFrom(