feat: record CLI version in manifest package (#184)

Record the current CLI version in the manifest package when we release
the manifest.

This by itself will not trigger a new release of the
`cloud-assembly-schema` package, so the version only gets recorded (and
published!) when there is a new version of `cloud-assembly-schema` to
publish anyway, and the version will only be displayed back to the user
if there is an incompatibility of the major version number.

That means we won't necessarily show the *lowest* possible CLI version
number when the user needs to upgrade, but we'll show a valid CLI
version number that will definitely support the given manifest.

---
By submitting this pull request, I confirm that my contribution is made
under the terms of the Apache-2.0 license

---------

Signed-off-by: github-actions <github-actions@github.com>
Co-authored-by: github-actions <github-actions@github.com>

Author: rix0rrr

.projenrc.ts

@@ -376,9 +376,17 @@ new JsiiBuild(cloudAssemblySchema, {
 (() => {
   cloudAssemblySchema.preCompileTask.exec('tsx projenrc/update.ts');
 
+  // This file will be generated at release time. It needs to be gitignored or it will
+  // fail projen's "no tamper" check, which means it must also be generated every build time.
+  //
+  // Crucially, this must also run during release after bumping, but that is satisfied already
+  // by making it part of preCompile, because that makes it run as part of projen build.
+  cloudAssemblySchema.preCompileTask.exec('tsx ../../../projenrc/copy-cli-version-to-assembly.task.ts');
+  cloudAssemblySchema.gitignore.addPatterns('cli-version.json');
+
   cloudAssemblySchema.addPackageIgnore('*.ts');
   cloudAssemblySchema.addPackageIgnore('!*.d.ts');
-  cloudAssemblySchema.addPackageIgnore('** /scripts');
+  cloudAssemblySchema.addPackageIgnore('**/scripts');
 })();
 
 //////////////////////////////////////////////////////////////////////

packages/@aws-cdk/cloud-assembly-schema/.gitignore

@@ -13,6 +13,15 @@ import * as integ from './integ-tests';
 // see exec.ts#createAssembly
 export const VERSION_MISMATCH: string = 'Cloud assembly schema version mismatch';
 
+/**
+ * CLI version is created at build and release time
+ *
+ * It needs to be .gitignore'd, otherwise the projen 'no uncommitted
+ * changes' self-check will fail, which means it needs to be generated
+ * at build time if it doesn't already exist.
+ */
+import CLI_VERSION = require('../cli-version.json');
+
 import ASSETS_SCHEMA = require('../schema/assets.schema.json');
 
 import ASSEMBLY_SCHEMA = require('../schema/cloud-assembly.schema.json');
@@ -141,6 +150,14 @@ export class Manifest {
     return `${SCHEMA_VERSION.revision}.0.0`;
   }
 
+  /**
+   * Return the CLI version that supports this Cloud Assembly Schema version
+   */
+  public static cliVersion(): string | undefined {
+    const version = CLI_VERSION.version;
+    return version ? version : undefined;
+  }
+
   /**
    * Deprecated
    * @deprecated use `saveAssemblyManifest()`
@@ -216,7 +233,11 @@ export class Manifest {
     schema: jsonschema.Schema,
     preprocess?: (obj: any) => any,
   ) {
-    let withVersion = { ...manifest, version: Manifest.version() };
+    let withVersion = {
+      ...manifest,
+      version: Manifest.version(),
+      minimumCliVersion: Manifest.cliVersion(),
+    } satisfies assembly.AssemblyManifest;
     Manifest.validate(withVersion, schema);
     if (preprocess) {
       withVersion = preprocess(withVersion);

packages/@aws-cdk/cloud-assembly-schema/.npmignore

@@ -1,3 +1,4 @@
+/* eslint-disable @typescript-eslint/no-require-imports */
 import * as fs from 'fs';
 import * as os from 'os';
 import * as path from 'path';
@@ -31,10 +32,36 @@ test('manifest save', () => {
 
   const saved = JSON.parse(fs.readFileSync(manifestFile, { encoding: 'utf-8' }));
 
-  expect(saved).toEqual({
+  expect(saved).toEqual(expect.objectContaining({
     ...assemblyManifest,
     version: Manifest.version(), // version is forced
-  });
+  }));
+});
+
+test('manifest contains minimum CLI version', () => {
+  const outdir = fs.mkdtempSync(path.join(os.tmpdir(), 'schema-tests'));
+  const manifestFile = path.join(outdir, 'manifest.json');
+
+  // This relies on the fact that the cli JSON version file is `require()`d,
+  // and that the 'require' below will find the same object in the module cache.
+  const cliVersionFile = require(`${__dirname}/../cli-version.json`);
+  cliVersionFile.version = '9.9.9';
+  try {
+    const assemblyManifest: AssemblyManifest = {
+      version: 'version',
+      runtime: {
+        libraries: { lib1: '1.2.3' },
+      },
+    };
+
+    Manifest.saveAssemblyManifest(assemblyManifest, manifestFile);
+
+    const saved = JSON.parse(fs.readFileSync(manifestFile, { encoding: 'utf-8' }));
+
+    expect(saved.minimumCliVersion).toEqual('9.9.9');
+  } finally {
+    cliVersionFile.version = '';
+  }
 });
 
 test('assumeRoleAdditionalOptions.RoleArn is validated in stack artifact', () => {

packages/@aws-cdk/cloud-assembly-schema/.projen/tasks.json

@@ -0,0 +1,24 @@
+import { promises as fs } from 'fs';
+
+/**
+ * Copy the version from the CLI into the `@aws-cdk/cloud-assembly-schema` package at release time.
+ */
+async function main() {
+  const cliVersion = JSON.parse(await fs.readFile(`${__dirname}/../packages/aws-cdk/package.json`, 'utf8')).version;
+
+  const cliVersionFile = `${__dirname}/../packages/@aws-cdk/cloud-assembly-schema/cli-version.json`;
+
+  // We write an empty string if we're in "development mode" to show that we don't really have a version.
+  // It's not a missing field so that the `import` statement of that JSON file in TypeScript
+  // always knows the version field is there, and its value is a string.
+  const advertisedVersion = cliVersion !== '0.0.0' ? cliVersion : '';
+
+  await fs.writeFile(cliVersionFile, JSON.stringify({ version: advertisedVersion }), 'utf8');
+}
+
+main().catch(e => {
+  // this is effectively a mini-cli
+  // eslint-disable-next-line no-console
+  console.error(e);
+  process.exitCode = 1;
+});