Implement automatically binding string-interpolated values (#56)

* Implement autom-binding with string interpolation

* Implement automatic binding in existing `raw` method

This removes the old `bind()` API.

* Update to auto-generated Linux test file

* Clean up and make Fragement internal

Sources/SQLKit/Builders/SQLRawBuilder.swift

@@ -1,55 +1,24 @@
 /// Builds raw SQL queries.
 ///
-///     conn.raw("SELECT * FROM planets WHERE name = ?")
-///         .bind("Earth")
+///     conn.raw("SELECT * FROM planets WHERE name = \(bind: "Earth")")
 ///         .all(decoding: Planet.self)
 ///
 public final class SQLRawBuilder: SQLQueryBuilder, SQLQueryFetcher {
     /// Raw query being built.
-    public var sql: String
-
-    /// Bound values.
-    public var binds: [Encodable]
-
+    var sql: SQLQueryString
+
     /// See `SQLQueryBuilder`.
     public var database: SQLDatabase
-    
+
     /// See `SQLQueryBuilder`.
     public var query: SQLExpression {
-        return SQLRaw(self.sql)
+        return self.sql
     }
-    
+
     /// Creates a new `SQLRawBuilder`.
-    public init(_ sql: String, on database: SQLDatabase) {
-        self.sql = sql
+    public init(_ sql: SQLQueryString, on database: SQLDatabase) {
         self.database = database
-        self.binds = []
-    }
-
-    /// Binds a single encodable value to the query. Each bind should
-    /// correspond to a placeholder in the query string.
-    ///
-    ///     conn.raw("SELECT * FROM planets WHERE name = ?")
-    ///         .bind("Earth")
-    ///         .all(decoding: Planet.self)
-    ///
-    /// This method can be chained multiple times.
-    public func bind(_ encodable: Encodable) -> Self {
-        self.binds.append(encodable)
-        return self
-    }
-
-    /// Binds an array of encodable values to the query. Each item in the
-    /// array should correspond to a placeholder in the query string.
-    ///
-    ///     conn.raw("SELECT * FROM planets WHERE name = ? OR name = ?")
-    ///         .binds(["Earth", "Mars"])
-    ///         .all(decoding: Planet.self)
-    ///
-    /// This method can be chained multiple times.
-    public func binds(_ encodables: [Encodable]) -> Self {
-        self.binds += encodables
-        return self
+        self.sql = sql
     }
 }
 
@@ -63,7 +32,7 @@ extension SQLDatabase {
     /// - parameters:
     ///     - sql: The SQL query string.
     /// - returns: `SQLRawBuilder`.
-    public func raw(_ sql: String) -> SQLRawBuilder {
+    public func raw(_ sql: SQLQueryString) -> SQLRawBuilder {
         return .init(sql, on: self)
     }
 }

Sources/SQLKit/Query/SQLQueryString.swift

@@ -0,0 +1,53 @@
+public struct SQLQueryString {
+    enum Fragment {
+        case literal(String)
+        case value(Encodable)
+    }
+
+    var fragments: [Fragment]
+}
+
+extension SQLQueryString: ExpressibleByStringLiteral {
+    public init(stringLiteral value: String) {
+        fragments = [.literal(value)]
+    }
+}
+
+extension SQLQueryString: ExpressibleByStringInterpolation {
+
+    public init(stringInterpolation: SQLQueryString) {
+        fragments = stringInterpolation.fragments
+    }
+}
+
+extension SQLQueryString: StringInterpolationProtocol {
+    public init(literalCapacity: Int, interpolationCount: Int) {
+        fragments = []
+    }
+
+    mutating public func appendLiteral(_ literal: String) {
+        fragments.append(.literal(literal))
+    }
+
+    mutating public func appendInterpolation(_ literal: String) {
+        fragments.append(.literal(literal))
+    }
+
+    mutating public func appendInterpolation(bind value: Encodable) {
+        fragments.append(.value(value))
+    }
+}
+
+extension SQLQueryString: SQLExpression {
+    public func serialize(to serializer: inout SQLSerializer) {
+        for fragment in fragments {
+            switch fragment {
+            case let .literal(str):
+                serializer.write(str)
+            case let .value(v):
+                serializer.dialect.nextBindPlaceholder().serialize(to: &serializer)
+                serializer.binds.append(v)
+            }
+        }
+    }
+}

Tests/LinuxMain.swift

@@ -1,28 +1,8 @@
 import XCTest
 
-@testable import SQLKitTests
+import SQLKitTests
 
-// MARK: SQLKitTests
+var tests = [XCTestCaseEntry]()
+tests += SQLKitTests.__allTests()
 
-extension SQLKitTests {
-	static let __allSQLKitTestsTests = [
-        ("testBenchmarker", testBenchmarker),
-        ("testLockingClause_forUpdate", testLockingClause_forUpdate),
-        ("testLockingClause_lockInShareMode", testLockingClause_lockInShareMode),
-	]
-}
-
-// MARK: Test Runner
-
-#if !os(macOS)
-public func __buildTestEntries() -> [XCTestCaseEntry] {
-	return [
-		// SQLKitTests
-		testCase(SQLKitTests.__allSQLKitTestsTests),
-	]
-}
-
-let tests = __buildTestEntries()
 XCTMain(tests)
-#endif
-

Tests/SQLKitTests/SQLKitTests.swift

@@ -28,4 +28,15 @@ final class SQLKitTests: XCTestCase {
             .run().wait()
         XCTAssertEqual(db.results[0], "SELECT * FROM `planets` WHERE `name` = ? LOCK IN SHARE MODE")
     }
+
+    func testRawQueryStringInterpolation() throws {
+        let db = TestDatabase()
+        let (table, planet) = ("planets", "Earth")
+        let builder = db.raw("SELECT * FROM \(table) WHERE name = \(bind: planet)")
+        var serializer = SQLSerializer(dialect: GenericDialect())
+        builder.query.serialize(to: &serializer)
+
+        XCTAssertEqual(serializer.sql, "SELECT * FROM planets WHERE name = ?")
+        XCTAssert(serializer.binds.first! as! String == "Earth")
+    }
 }

Tests/SQLKitTests/XCTestManifests.swift

@@ -0,0 +1,21 @@
+#if !canImport(ObjectiveC)
+import XCTest
+
+extension SQLKitTests {
+    // DO NOT MODIFY: This is autogenerated, use:
+    //   `swift test --generate-linuxmain`
+    // to regenerate.
+    static let __allTests__SQLKitTests = [
+        ("testBenchmarker", testBenchmarker),
+        ("testLockingClause_forUpdate", testLockingClause_forUpdate),
+        ("testLockingClause_lockInShareMode", testLockingClause_lockInShareMode),
+        ("testRawQueryStringInterpolation", testRawQueryStringInterpolation),
+    ]
+}
+
+public func __allTests() -> [XCTestCaseEntry] {
+    return [
+        testCase(SQLKitTests.__allTests__SQLKitTests),
+    ]
+}
+#endif