jsonSchemaToType: `{ type: "string", enum: [...] }` throws "Intersection of string and object results in an unsatisfiable type"

[graffhyrum]

Bug Report

jsonSchemaToType from @ark/json-schema throws a ParseError when given a schema that combines type: "string" with enum. This is a common JSON Schema pattern (the type annotation is redundant but valid per spec when all enum values are strings).

Package

@ark/json-schema v0.0.4

Repro

import { jsonSchemaToType } from "@ark/json-schema"

// ✅ works
jsonSchemaToType({ type: "string" })

// ✅ works
jsonSchemaToType({ enum: ["stable", "latest"] })

// ❌ throws: ParseError: Intersection of string and object results in an unsatisfiable type
jsonSchemaToType({ type: "string", enum: ["stable", "latest"] })

// ❌ also throws (default + enum + type)
jsonSchemaToType({ type: "string", enum: ["stable", "latest"], default: "latest" })

// ❌ also throws when nested inside an object property
jsonSchemaToType({
  type: "object",
  properties: {
    mode: { type: "string", enum: ["append", "replace"] }
  }
})

Expected behavior

{ type: "string", enum: ["stable", "latest"] } should produce the equivalent of type("'stable' | 'latest'"). Per JSON Schema spec, when type and enum are combined, the type annotation is informational — the enum constraint already restricts the valid values.

Actual behavior

ParseError: Intersection of string and object results in an unsatisfiable type
    at throwError (node_modules/@ark/util/out/errors.js:5:11)
    at applyMorphsAtPath (node_modules/@ark/schema/out/shared/traversal.js:184:28)
    at applyQueuedMorphs (node_modules/@ark/schema/out/shared/traversal.js:166:22)
    at finalize (node_modules/@ark/schema/out/shared/traversal.js:109:18)
    at <anonymous> (node_modules/@ark/json-schema/out/object.js:103:20)

The library appears to process type: "string" and enum as separate constraints and then intersect them, producing string & object = unsatisfiable, rather than recognising that enum with all-string values is already a string subtype.

Context

Encountered while trying to use jsonSchemaToType with the Claude Code settings JSON Schema, which uses { type: "string", enum: [...] } for several properties (autoUpdatesChannel, effortLevel, forceLoginMethod, spinnerVerbs.mode, teammateMode).

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