JSON schema override is not applied when schema is overridden #5499
Description
Test case:
const z = require('zod');
const schema = z.enum(['foo', 'bar']).meta({ foo: 'bar' });
const objectSchema = z.object({
foo: schema.meta({ bar: 'zap' }),
baz: z.array(schema),
});
const rendered = z.toJSONSchema(objectSchema, {
io: 'output',
override: ctx => {
if (ctx.jsonSchema.type === 'string') {
ctx.jsonSchema.thisShouldAlwaysAppear = 'in the output';
}
},
});
console.log(JSON.stringify(rendered, null, 2));This outputs the following:
{
"$schema": "https://json-schema.org/draft/2020-12/schema",
"type": "object",
"properties": {
"foo": {
"foo": "bar",
"bar": "zap",
"type": "string",
"enum": [
"foo",
"bar"
],
"thisShouldAlwaysAppear": "in the output"
},
"baz": {
"type": "array",
"items": {
"foo": "bar",
"type": "string",
"enum": [
"foo",
"bar"
]
}
}
},
"required": [
"foo",
"baz"
],
"additionalProperties": false
}
Notice that "thisShouldAlwaysAppear": "in the output" does not appear for the second instance.
This is using zod 4.1.13 and appears to be caused by this check:
https://github.com/colinhacks/zod/blob/main/packages/zod/src/v4/core/to-json-schema.ts#L828
Because the original schema is considered a parent, it is not overridden.