Schema: JSONSchema should support make(Class) (#2579)

.changeset/hot-items-complain.md

@@ -0,0 +1,33 @@
+---
+"@effect/schema": patch
+---
+
+Schema: JSONSchema should support make(Class)
+
+Before
+
+```ts
+import { JSONSchema, Schema } from "@effect/schema"
+
+class A extends Schema.Class<A>("A")({
+  a: Schema.String
+}) {}
+
+console.log(JSONSchema.make(A)) // throws MissingAnnotation: cannot build a JSON Schema for a declaration without a JSON Schema annotation
+```
+
+Now
+
+```ts
+console.log(JSONSchema.make(A))
+/*
+Output:
+{
+  '$schema': 'http://json-schema.org/draft-07/schema#',
+  type: 'object',
+  required: [ 'a' ],
+  properties: { a: { type: 'string', description: 'a string', title: 'string' } },
+  additionalProperties: false
+}
+*/
+```

packages/schema/src/JSONSchema.ts

@@ -278,6 +278,10 @@ export const DEFINITION_PREFIX = "#/$defs/"
 const get$ref = (id: string): string => `${DEFINITION_PREFIX}${id}`
 
 const go = (ast: AST.AST, $defs: Record<string, JsonSchema7>, handleIdentifier: boolean = true): JsonSchema7 => {
+  const surrogate = AST.getSurrogateAnnotation(ast)
+  if (Option.isSome(surrogate)) {
+    return go(surrogate.value, $defs, handleIdentifier)
+  }
   const hook = AST.getJSONSchemaAnnotation(ast)
   if (Option.isSome(hook)) {
     const handler = hook.value as JsonSchema7

packages/schema/test/JSONSchema.test.ts

@@ -1523,7 +1523,27 @@ describe("JSONSchema", () => {
   })
 
   describe("Class", () => {
-    it("should support S.encodedSchema(Class)", () => {
+    it("should support make(Class)", () => {
+      class A extends S.Class<A>("A")({ a: S.String }) {}
+      const jsonSchema = JSONSchema.make(A)
+      expect(jsonSchema).toEqual({
+        "$schema": "http://json-schema.org/draft-07/schema#",
+        "type": "object",
+        "required": [
+          "a"
+        ],
+        "properties": {
+          "a": {
+            "type": "string",
+            "description": "a string",
+            "title": "string"
+          }
+        },
+        "additionalProperties": false
+      })
+    })
+
+    it("should support make(S.encodedSchema(Class))", () => {
       class A extends S.Class<A>("A")({ a: S.String }) {}
       const jsonSchema = JSONSchema.make(S.encodedSchema(A))
       expect(jsonSchema).toEqual({