much simpler approach! post-process

packages/turbo-types/scripts/generate-schema.ts

@@ -2,96 +2,49 @@
 
 import { writeFileSync } from "node:fs";
 import { join } from "node:path";
-import {
-  DEFAULT_CONFIG,
-  SchemaGenerator,
-  createFormatter,
-  createParser,
-  createProgram,
-  ts, // use the reexported TypeScript to avoid version conflicts
-  type CompletedConfig,
-} from "ts-json-schema-generator";
+import { createGenerator } from "ts-json-schema-generator";
 
 const __dirname = new URL(".", import.meta.url).pathname;
 const packageRoot = join(__dirname, "..", "src");
 
 /**
- * Unfortunately, we find ourselves in a world where TSDoc and TypeDoc use `@defaultValue`, expecting backticks around the value, while JSON Schema uses `default` without backticks.
- *
- * This function replaces `@defaultValue` with `@default` and removes backticks from the value.
- *
- * Needless to say, this is something that's pretty hacky to do, but ts-json-schema-generator doesn't provide a way to customize this behavior, so modifying the file with the TypeScript API (i.e. before it gets to the generator) is our only option.
+ * post-process the schema recursively to:
+ * 1. replace any key named `defaultValue` with `default`
+ * 1. remove any backticks from the value
+ * 1. attempt to parsing the value as JSON (falling back, if not)
  */
-const replaceJSDoc = (
-  node: ts.Node,
-  context: ts.TransformationContext
-): ts.Node => {
-  if ("jsDoc" in node && Array.isArray(node.jsDoc)) {
-    node.jsDoc.forEach((jsDoc: ts.Node) => {
-      if (ts.isJSDoc(jsDoc)) {
-        if (jsDoc.tags !== undefined && jsDoc.tags.length > 0) {
-          jsDoc.tags.forEach((tag) => {
-            if (tag.tagName.text === "defaultValue") {
-              // @ts-expect-error TypeScript doesn't want us to be able to assign to a readonly value here
-              // eslint-disable-next-line @typescript-eslint/no-unsafe-assignment, @typescript-eslint/no-unsafe-call -- we're messing with TypeScript's internals here
-              tag.tagName.escapedText = tag.tagName.escapedText.replace(
-                "defaultValue",
-                "default"
-              );
-              if (typeof tag.comment === "string") {
-                // @ts-expect-error TypeScript doesn't want us to be able to assign to a readonly value here
-                tag.comment = tag.comment.replaceAll("`", "");
-              }
-            }
-          });
+const postProcess = <T>(item: T): T => {
+  if (typeof item !== "object" || item === null) {
+    return item;
+  }
+  if (Array.isArray(item)) {
+    return item.map(postProcess) as unknown as T;
+  }
+  return Object.fromEntries(
+    Object.entries(item).map(([key, value]) => {
+      if (key === "defaultValue" && typeof value === "string") {
+        const replaced = value.replaceAll(/`/g, "");
+        try {
+          return ["default", JSON.parse(replaced)];
+        } catch (e) {
+          return ["default", replaced];
         }
       }
-    });
-  }
-
-  return ts.visitEachChild(
-    node,
-    (child) => replaceJSDoc(child, context),
-    context
-  );
-};
-
-const updateJSDoc = (program: ts.Program) => {
-  const sourceFiles = program.getSourceFiles();
-  sourceFiles
-    .filter((sourceFile) => sourceFile.fileName.includes(packageRoot))
-    .forEach((sourceFile) => {
-      ts.transform(sourceFile, [
-        (context) => (rootNode) => {
-          rootNode.forEachChild((node) => {
-            replaceJSDoc(node, context);
-          });
-          return rootNode;
-        },
-      ]);
-    });
+      return [key, postProcess(value)];
+    })
+  ) as T;
 };
 
 const create = (fileName: string, typeName: string) => {
-  const config: CompletedConfig = {
-    ...DEFAULT_CONFIG,
+  const generator = createGenerator({
     path: join(packageRoot, "index.ts"),
     tsconfig: join(__dirname, "../tsconfig.json"),
     type: "Schema",
-  };
-
-  const program = createProgram(config);
-
-  updateJSDoc(program);
-
-  const parser = createParser(program, config);
-
-  const formatter = createFormatter(config);
-  const generator = new SchemaGenerator(program, parser, formatter, config);
-  const schema = generator.createSchema(typeName);
+    extraTags: ["defaultValue"],
+  });
+  const schema = postProcess(generator.createSchema(typeName));
   const filePath = join(__dirname, "..", "schemas", fileName);
-  const fileContents = JSON.stringify(schema, null, 2);
-  writeFileSync(filePath, fileContents);
+  writeFileSync(filePath, JSON.stringify(schema, null, 2));
 };
 
 create("schema.v1.json", "SchemaV1");