Merge pull request #220 from vapor/zero-length-arr

add support for encoding zero-length arrays

Author: tanner0101

Sources/MySQL/Codable/MySQLDataEncoder.swift

@@ -8,18 +8,13 @@ struct MySQLDataEncoder {
             let encoder = _Encoder()
             do {
                 try value.encode(to: encoder)
-                return encoder.data!
-            } catch is _DoJSONError {
-                struct AnyEncodable: Encodable {
-                    let encodable: Encodable
-                    init(_ encodable: Encodable) {
-                        self.encodable = encodable
-                    }
-                    func encode(to encoder: Encoder) throws {
-                        try encodable.encode(to: encoder)
-                    }
+                if let data = encoder.data {
+                    return data
+                } else {
+                    return self.encode(json: value)
                 }
-                return .init(json: AnyEncodable(value))
+            } catch is _DoJSONError {
+                return self.encode(json: value)
             } catch {
                 ERROR("Could not encode \(type(of: value)) to MySQLData: \(error)")
                 return .null
@@ -28,6 +23,19 @@ struct MySQLDataEncoder {
     }
 
     // MARK: Private
+    
+    private func encode(json value: Encodable) -> MySQLData {
+        struct AnyEncodable: Encodable {
+            let encodable: Encodable
+            init(_ encodable: Encodable) {
+                self.encodable = encodable
+            }
+            func encode(to encoder: Encoder) throws {
+                try encodable.encode(to: encoder)
+            }
+        }
+        return .init(json: AnyEncodable(value))
+    }
 
     private final class _Encoder: Encoder {
         let codingPath: [CodingKey] = []

Tests/MySQLTests/MySQLTests.swift

@@ -331,6 +331,13 @@ class MySQLTests: XCTestCase {
         XCTAssertEqual(res2.count, 0)
     }
 
+    // https://github.com/vapor/mysql/issues/221
+    func testZeroLengthArray() throws {
+        let arr: [Int] = []
+        let data = MySQLDataEncoder().encode(arr)
+        print(data)
+    }
+    
     static let allTests = [
         ("testBenchmark", testBenchmark),
         ("testSimpleQuery", testSimpleQuery),
@@ -349,6 +356,7 @@ class MySQLTests: XCTestCase {
         ("testColumnAfter", testColumnAfter),
         ("testDecimalPrecision", testDecimalPrecision),
         ("testZeroRowSelect", testZeroRowSelect),
+        ("testZeroLengthArray", testZeroLengthArray),
     ]
 }