refactor: modularize validator and type declaration logic

src/type-utils.ts

@@ -0,0 +1,111 @@
+import type {
+  Schema,
+  ReferenceSchema,
+  ReverseReferenceSchema,
+  UnionSchema,
+} from "./types";
+
+export function schemaToTypeString(
+  schema: Schema,
+  resourceNames?: Map<string, string>,
+): string {
+  switch (schema.type) {
+    case "string":
+      return "string";
+    case "number":
+    case "int":
+    case "float":
+      return "number";
+    case "boolean":
+      return "boolean";
+    case "stringLiteral":
+      return `"${schema.value}"`;
+    case "union":
+      return schema.members
+        .map((m) => schemaToTypeString(m, resourceNames))
+        .join(" | ");
+    case "reference": {
+      const typeName =
+        resourceNames?.get(schema.tableName) ||
+        schema.tableName.charAt(0).toUpperCase() + schema.tableName.slice(1);
+      const baseType = schema.isArray ? `${typeName}[]` : typeName;
+      return schema.isOptional ? `${baseType} | null` : baseType;
+    }
+    case "reverseReference": {
+      const typeName =
+        resourceNames?.get(schema.tableName) ||
+        schema.tableName.charAt(0).toUpperCase() + schema.tableName.slice(1);
+      const baseType = `${typeName}[]`;
+      return schema.isOptional ? `${baseType} | null` : baseType;
+    }
+    case "array":
+      if (schema.element.type === "tuple") {
+        const tupleElements = schema.element.elements.map((el) => {
+          const typeStr = schemaToTypeString(el.schema, resourceNames);
+          return el.name ? `${el.name}: ${typeStr}` : typeStr;
+        });
+        return `[${tupleElements.join(", ")}][]`;
+      }
+      const elementType = schemaToTypeString(schema.element, resourceNames);
+      if (schema.element.type === "union") {
+        return `(${elementType})[]`;
+      }
+      return `${elementType}[]`;
+    case "tuple":
+      const tupleElements = schema.elements.map((el) => {
+        const typeStr = schemaToTypeString(el.schema, resourceNames);
+        return el.name ? `${el.name}: ${typeStr}` : typeStr;
+      });
+      return `[${tupleElements.join(", ")}]`;
+    default:
+      return "unknown";
+  }
+}
+
+export function createValidator(schema: Schema): (value: unknown) => boolean {
+  return function validate(value: unknown): boolean {
+    switch (schema.type) {
+      case "string":
+        return typeof value === "string";
+      case "number":
+        return typeof value === "number" && !isNaN(value);
+      case "int":
+        return (
+          typeof value === "number" && !isNaN(value) && Number.isInteger(value)
+        );
+      case "float":
+        return typeof value === "number" && !isNaN(value);
+      case "boolean":
+        return typeof value === "boolean";
+      case "stringLiteral":
+        return typeof value === "string" && value === schema.value;
+      case "union":
+        return schema.members.some((member) => createValidator(member)(value));
+      case "tuple":
+        if (!Array.isArray(value)) return false;
+        if (value.length !== schema.elements.length) return false;
+        return schema.elements.every((elementSchema, index) =>
+          createValidator(elementSchema.schema)(value[index]),
+        );
+      case "array":
+        if (!Array.isArray(value)) return false;
+        return value.every((item) => createValidator(schema.element)(item));
+      case "reference":
+        if (schema.isOptional && value === null) return true;
+        if (schema.isArray) {
+          return (
+            Array.isArray(value) && value.every((id) => typeof id === "string")
+          );
+        }
+        return (
+          typeof value === "string" ||
+          (Array.isArray(value) && value.every((id) => typeof id === "string"))
+        );
+      case "reverseReference":
+        if (schema.isOptional && value === null) return true;
+        return Array.isArray(value);
+      default:
+        return false;
+    }
+  };
+}