Fix: Correct Handling of JSON Schema Annotations in Refinements (#3284)

.changeset/neat-spoons-cheer.md

@@ -0,0 +1,41 @@
+---
+"@effect/schema": patch
+---
+
+Fix: Correct Handling of JSON Schema Annotations in Refinements
+
+Fixes an issue where the JSON schema annotation set by a refinement after a transformation was mistakenly interpreted as an override annotation. This caused the output to be incorrect, as the annotations were not applied as intended.
+
+Before
+
+```ts
+import { JSONSchema, Schema } from "@effect/schema"
+
+const schema = Schema.Trim.pipe(Schema.nonEmpty())
+
+const jsonSchema = JSONSchema.make(schema)
+console.log(JSON.stringify(jsonSchema, null, 2))
+/*
+{
+  "$schema": "http://json-schema.org/draft-07/schema#",
+  "minLength": 1
+}
+*/
+```
+
+Now
+
+```ts
+import { JSONSchema, Schema } from "@effect/schema"
+
+const schema = Schema.Trim.pipe(Schema.nonEmpty())
+
+const jsonSchema = JSONSchema.make(schema)
+console.log(JSON.stringify(jsonSchema, null, 2))
+/*
+{
+  "$schema": "http://json-schema.org/draft-07/schema#",
+  "type": "string"
+}
+*/
+```

packages/schema/src/JSONSchema.ts

@@ -281,22 +281,19 @@ export const DEFINITION_PREFIX = "#/$defs/"
 
 const get$ref = (id: string): string => `${DEFINITION_PREFIX}${id}`
 
-const hasTransformation = (ast: AST.Refinement): boolean => {
+const getRefinementInnerTransformation = (ast: AST.Refinement): AST.AST | undefined => {
   switch (ast.from._tag) {
     case "Transformation":
-      return true
+      return ast.from
     case "Refinement":
-      return hasTransformation(ast.from)
-    case "Suspend":
-      {
-        const from = ast.from.f()
-        if (AST.isRefinement(from)) {
-          return hasTransformation(from)
-        }
+      return getRefinementInnerTransformation(ast.from)
+    case "Suspend": {
+      const from = ast.from.f()
+      if (AST.isRefinement(from)) {
+        return getRefinementInnerTransformation(from)
       }
-      break
+    }
   }
-  return false
 }
 
 const isParseJsonTransformation = (ast: AST.AST): boolean =>
@@ -309,6 +306,11 @@ function merge(a: object, b: object): object {
   return { ...a, ...b }
 }
 
+const isOverrideAnnotation = (jsonSchema: JsonSchema7): boolean => {
+  return ("type" in jsonSchema) || ("oneOf" in jsonSchema) || ("anyOf" in jsonSchema) || ("const" in jsonSchema) ||
+    ("enum" in jsonSchema) || ("$ref" in jsonSchema)
+}
+
 const go = (
   ast: AST.AST,
   $defs: Record<string, JsonSchema7>,
@@ -318,11 +320,16 @@ const go = (
   const hook = AST.getJSONSchemaAnnotation(ast)
   if (Option.isSome(hook)) {
     const handler = hook.value as JsonSchema7
-    if (AST.isRefinement(ast) && !hasTransformation(ast)) {
-      try {
-        return merge(merge(go(ast.from, $defs, true, path), getJsonSchemaAnnotations(ast)), handler)
-      } catch (e) {
-        return merge(getJsonSchemaAnnotations(ast), handler)
+    if (AST.isRefinement(ast)) {
+      const t = getRefinementInnerTransformation(ast)
+      if (t === undefined) {
+        try {
+          return merge(merge(go(ast.from, $defs, true, path), getJsonSchemaAnnotations(ast)), handler)
+        } catch (e) {
+          return merge(getJsonSchemaAnnotations(ast), handler)
+        }
+      } else if (!isOverrideAnnotation(handler)) {
+        return go(t, $defs, true, path)
       }
     }
     return handler

packages/schema/test/JSONSchema.test.ts

@@ -1866,12 +1866,57 @@ schema (Suspend): <suspended schema>`
       }, false)
     })
 
-    it("refinement of a transformation", () => {
+    it("refinement of a transformation with an override annotation", () => {
       expectJSONSchema(Schema.Date.annotations({ jsonSchema: { type: "string", format: "date-time" } }), {
         "$schema": "http://json-schema.org/draft-07/schema#",
         "format": "date-time",
         "type": "string"
       }, false)
+      expectJSONSchema(
+        Schema.Date.annotations({
+          jsonSchema: { oneOf: [{ type: "object" }, { type: "array" }] }
+        }),
+        { "$schema": "http://json-schema.org/draft-07/schema#", oneOf: [{ type: "object" }, { type: "array" }] },
+        false
+      )
+      expectJSONSchema(
+        Schema.Date.annotations({
+          jsonSchema: { anyOf: [{ type: "object" }, { type: "array" }] }
+        }),
+        { "$schema": "http://json-schema.org/draft-07/schema#", anyOf: [{ type: "object" }, { type: "array" }] },
+        false
+      )
+      expectJSONSchema(Schema.Date.annotations({ jsonSchema: { $ref: "x" } }), {
+        "$schema": "http://json-schema.org/draft-07/schema#",
+        $ref: "x"
+      }, false)
+      expectJSONSchema(Schema.Date.annotations({ jsonSchema: { const: 1 } }), {
+        "$schema": "http://json-schema.org/draft-07/schema#",
+        const: 1
+      }, false)
+      expectJSONSchema(Schema.Date.annotations({ jsonSchema: { enum: [1] } }), {
+        "$schema": "http://json-schema.org/draft-07/schema#",
+        enum: [1]
+      }, false)
+    })
+
+    it("refinement of a transformation without an override annotation", () => {
+      expectJSONSchema(Schema.Trim.pipe(Schema.nonEmpty()), {
+        "$schema": "http://json-schema.org/draft-07/schema#",
+        "type": "string"
+      }, false)
+      expectJSONSchema(Schema.Trim.pipe(Schema.nonEmpty({ jsonSchema: { title: "Description" } })), {
+        "$schema": "http://json-schema.org/draft-07/schema#",
+        "type": "string"
+      }, false)
+      expectJSONSchema(
+        Schema.Trim.pipe(Schema.nonEmpty()).annotations({ jsonSchema: { title: "Description" } }),
+        {
+          "$schema": "http://json-schema.org/draft-07/schema#",
+          "type": "string"
+        },
+        false
+      )
     })
   })