Emit schema.ts as a giant string

Author: nirinchev

packages/mql-typescript/out/schema-export.js

@@ -47,7 +47,7 @@
     "reformat": "npm run prettier -- --write .",
     "extract-metaschema": "json-refs resolve mongo-php-library/generator/config/schema.json | json-schema-to-zod -n Operator -o src/metaschema.ts && npm run prettier -- --write src/metaschema.ts",
     "pregenerate-schema": "npm run extract-metaschema",
-    "generate-schema": "ts-node src/cli.ts schema && npm run prettier -- --write out/schema.ts",
+    "generate-schema": "ts-node src/cli.ts schema && npm run prettier -- --write out/*",
     "pregenerate-tests": "npm run extract-metaschema",
     "generate-tests": "ts-node src/cli.ts tests && npm run prettier -- --write tests/**/*.ts",
     "pregenerate-driver-schema": "npm run extract-metaschema",

packages/mql-typescript/package.json

@@ -1,3 +1,4 @@
+import type { WriteStream } from 'fs';
 import { createWriteStream } from 'fs';
 import { StringWriter } from './utils';
 import path from 'path';
@@ -29,7 +30,7 @@ class BsonDate extends Date {
 
 export abstract class GeneratorBase {
   private outputBuffer: StringWriter | undefined;
-  private outputStream?: NodeJS.WritableStream;
+  private outputStream?: WriteStream;
 
   constructor() {
     // The default YAML schema will represent BsonDate using the Date representation because
@@ -232,10 +233,28 @@ export abstract class GeneratorBase {
     }
   }
 
-  protected emitToFile(filePath: string): void {
+  protected async emitToFile(filePath: string): Promise<void> {
+    await this.flushFile();
+
     this.outputStream = createWriteStream(filePath, { encoding: 'utf8' });
   }
 
+  private flushFile(): Promise<void> {
+    if (this.outputStream) {
+      return new Promise((resolve, reject) => {
+        this.outputStream?.close((err) => {
+          if (err) {
+            reject(err);
+          } else {
+            resolve();
+          }
+        });
+      });
+    }
+
+    return Promise.resolve();
+  }
+
   protected emit(str: string): void {
     (this.outputBuffer ?? this.outputStream ?? process.stdout).write(str);
   }
@@ -275,7 +294,7 @@ export abstract class GeneratorBase {
 
   protected abstract generateImpl(iterable: YamlFiles): Promise<void>;
 
-  public generate(
+  public async generate(
     categoryFilter?: string,
     operatorFilter?: string,
   ): Promise<void> {
@@ -287,6 +306,8 @@ export abstract class GeneratorBase {
       : undefined;
 
     const files = this.listSourceYAMLFiles(categoryRegex, operatorRegex);
-    return this.generateImpl(files);
+    await this.generateImpl(files);
+
+    await this.flushFile();
   }
 }

packages/mql-typescript/src/generator.ts

@@ -3,6 +3,7 @@ import type { YamlFiles } from './generator';
 import { GeneratorBase } from './generator';
 import { Operator } from './metaschema';
 import { capitalize } from './utils';
+import * as fs from 'fs/promises';
 
 type ArgType = NonNullable<
   typeof Operator._type.arguments
@@ -13,10 +14,13 @@ type SyntheticVariables = NonNullable<
 >[number]['syntheticVariables'];
 
 export class SchemaGenerator extends GeneratorBase {
-  constructor() {
-    super();
-    this.emitToFile(path.resolve(__dirname, '..', 'out', 'schema.ts'));
-  }
+  private schemaOutputFile = path.resolve(__dirname, '..', 'out', 'schema.ts');
+  private schemaExportFile = path.resolve(
+    __dirname,
+    '..',
+    'out',
+    'schema-export.js',
+  );
 
   private toTypeName(type: string): string {
     return this.trivialTypeMappings[type as ArgType] ?? capitalize(type);
@@ -408,6 +412,8 @@ export class SchemaGenerator extends GeneratorBase {
   }
 
   protected override async generateImpl(yamlFiles: YamlFiles): Promise<void> {
+    await this.emitToFile(this.schemaOutputFile);
+
     this.emitHeader();
 
     for await (const file of yamlFiles) {
@@ -569,5 +575,19 @@ export class SchemaGenerator extends GeneratorBase {
         } = ${[...new Set(interfaces)].join('|')};`,
       );
     }
+
+    // Generate the schema-export.js which will be used by the autocomplete package to load the types
+    // Switch to the new file that will just export the types as a giant string:
+    // exports.schema = "** contents of the out/schema.ts file **";
+    await this.emitToFile(this.schemaExportFile);
+    const schemaDefinition = await fs.readFile(this.schemaOutputFile, 'utf8');
+    this.emit("exports.schema = '");
+    this.emit(
+      schemaDefinition
+        .replace(/\\/g, '\\\\') // Escape backslashes
+        .replace(/'/g, "\\'") // Escape double quotes
+        .replace(/\n/g, '\\n'), // Escape newlines
+    );
+    this.emit("'\n");
   }
 }