chore: store schema version inside package

(Take 2 of #62).

Currently, the schema version espoused by this package is the package
version itself (i.e., the version of its own `package.json`). Move this
version to a resource file that maintained inside the package and is
bumped explicitly.

In a projen (mono)repo, all packages have version 0.0.0. At development
time, the Cloud Assembly Schema has to know its own version, for various
versioning checks. It can’t get it from the package version (which is
0.0.0, so it needs to get it elsewhere, which will be
schema.version.json).

.projenrc.ts

@@ -3,6 +3,8 @@ import { JsonPatch, cdk } from 'projen';
 import { Stability } from 'projen/lib/cdk';
 import { TrailingComma } from 'projen/lib/javascript';
 
+const SCHEMA_VERSION: typeof import('./schema/version.json') = require('./schema/version.json');
+
 export const project = new cdk.JsiiProject({
   author: 'Amazon Web Services',
   authorAddress: '',
@@ -55,7 +57,8 @@ export const project = new cdk.JsiiProject({
       printWidth: 100,
     },
   },
-  nextVersionCommand: 'tsx ./projenrc/next-version.ts',
+  // This forces the next release to be the major version from the data file
+  minMajorVersion: SCHEMA_VERSION.revision,
   eslintOptions: {
     prettier: true,
     dirs: ['lib'],

lib/manifest.ts

@@ -22,7 +22,7 @@ import INTEG_SCHEMA = require('../schema/integ.schema.json');
 /**
  * Version is shared for both manifests
  */
-const SCHEMA_VERSION = require('../package.json').version;
+import SCHEMA_VERSION = require('../schema/version.json');
 
 /**
  * Options for the loadManifest operation
@@ -138,7 +138,7 @@ export class Manifest {
    * Fetch the current schema version number.
    */
   public static version(): string {
-    return SCHEMA_VERSION;
+    return `${SCHEMA_VERSION.revision}.0.0`;
   }
 
   /**

projenrc/update.ts

@@ -1,10 +1,13 @@
 import { SCHEMAS } from './schema-definition';
 import { generateSchema } from './update-schema';
+import { maybeBumpVersion } from './versioning';
 
 function update() {
+  const schemas: Record<string, any> = {};
   for (const s of SCHEMAS) {
-    generateSchema(s);
+    schemas[s] = generateSchema(s);
   }
+  maybeBumpVersion(schemas);
 }
 
 update();

projenrc/versioning.ts

@@ -0,0 +1,43 @@
+import * as crypto from 'crypto';
+import * as fs from 'fs';
+import * as path from 'path';
+import { SCHEMA_DIR } from './schema-definition';
+
+export function maybeBumpVersion(schemas: Record<string, any>) {
+  const serializedSchema = JSON.stringify(sortJson(schemas), null, 2);
+
+  const versionFile = path.join(SCHEMA_DIR, 'version.json');
+  let current: SchemaVersionFile = JSON.parse(fs.readFileSync(versionFile, 'utf8'));
+  const schemaHash = sha256(serializedSchema);
+
+  if (current.schemaHash !== schemaHash) {
+    current = { schemaHash, revision: current.revision + 1 };
+  }
+
+  fs.writeFileSync(versionFile, JSON.stringify(current, null, 2));
+}
+
+function sha256(x: string) {
+  const hash = crypto.createHash('sha256');
+  hash.update(x);
+  return hash.digest('hex');
+}
+
+interface SchemaVersionFile {
+  revision: number;
+  schemaHash: string;
+}
+
+function sortJson<A>(x: A): A {
+  if (Array.isArray(x)) {
+    return x;
+  }
+  if (typeof x === 'object' && x !== null) {
+    const ret: Record<string, any> = {};
+    for (const key of Object.keys(x).sort()) {
+      ret[key] = sortJson((x as any)[key]);
+    }
+    return ret as any;
+  }
+  return x;
+}

schema/version.json

@@ -0,0 +1,4 @@
+{
+  "schemaHash": "f0ccc3212331af8a1c75830878d218fd667e5957063831be3b5bfd803b25f0cc",
+  "revision": 39
+}