完善 README 文档，添加功能特性、使用说明及开发脚本；在转换逻辑中支持嵌套对象构建

src/lib/converter.spec.ts

@@ -100,6 +100,27 @@ describe('convertData', () => {
 		const result = convertData(rows, mappings);
 		expect(result[0]).toEqual({ full_name: 'Alice' });
 	});
+
+	it('builds nested objects from dot-separated target keys', () => {
+		const mappings: MappingConfig[] = [
+			{ source: 'name', target: 'user.name', type: 'string', excludeIfEmpty: false, defaultValue: '', enabled: true },
+			{ source: 'age', target: 'user.age', type: 'number', excludeIfEmpty: false, defaultValue: '', enabled: true },
+			{ source: 'active', target: 'meta.active', type: 'boolean', excludeIfEmpty: false, defaultValue: '', enabled: true }
+		];
+		const result = convertData(rows, mappings);
+		expect(result[0]).toEqual({
+			user: { name: 'Alice', age: 30 },
+			meta: { active: true }
+		});
+	});
+
+	it('builds deeply nested objects', () => {
+		const mappings: MappingConfig[] = [
+			{ source: 'name', target: 'a.b.c.d', type: 'string', excludeIfEmpty: false, defaultValue: '', enabled: true }
+		];
+		const result = convertData(rows, mappings);
+		expect(result[0]).toEqual({ a: { b: { c: { d: 'Alice' } } } });
+	});
 });
 
 describe('date conversion', () => {

src/lib/converter.ts

@@ -63,6 +63,31 @@ function formatDate(value: unknown, format?: string): string | number {
 	return date.format(format || 'YYYY-MM-DD');
 }
 
+/**
+ * Set a value at a dot-separated path, creating nested objects as needed.
+ * e.g. setNested(obj, "user.address.city", "Beijing")
+ *   => obj = { user: { address: { city: "Beijing" } } }
+ */
+function setNested(obj: Record<string, unknown>, path: string, value: unknown): void {
+	if (!path.includes('.')) {
+		obj[path] = value;
+		return;
+	}
+
+	const keys = path.split('.');
+	let current: Record<string, unknown> = obj;
+
+	for (let i = 0; i < keys.length - 1; i++) {
+		const key = keys[i];
+		if (current[key] === undefined || current[key] === null || typeof current[key] !== 'object') {
+			current[key] = {};
+		}
+		current = current[key] as Record<string, unknown>;
+	}
+
+	current[keys[keys.length - 1]] = value;
+}
+
 /**
  * Convert raw Excel rows to JSON objects based on mapping configs.
  */
@@ -83,13 +108,13 @@ export function convertData(
 				continue;
 			}
 
-			if (isEmptyVal) {
-				obj[mapping.target] = mapping.defaultValue !== undefined && mapping.defaultValue !== ''
+			const finalValue = isEmptyVal
+				? (mapping.defaultValue !== undefined && mapping.defaultValue !== ''
 					? convertValue(mapping.defaultValue, mapping.type, mapping.format)
-					: null;
-			} else {
-				obj[mapping.target] = convertValue(rawValue, mapping.type, mapping.format);
-			}
+					: null)
+				: convertValue(rawValue, mapping.type, mapping.format);
+
+			setNested(obj, mapping.target, finalValue);
 		}
 
 		return obj;