Refactoring

Sources/DataRaft/Structures/Migration.swift

@@ -1,41 +1,52 @@
 import Foundation
-import DataLiteCore
 
-/// Represents a database migration step associated with a specific version.
+/// A database migration step for a specific schema version.
 ///
-/// Each `Migration` contains a reference to a migration script file (usually a `.sql` file) and the
-/// version to which this script corresponds. The script is expected to be bundled with the application.
+/// ## Overview
 ///
-/// You can initialize a migration directly with a URL to the script, or load it from a resource
-/// embedded in a bundle.
+/// Each migration links a version identifier with a script file that modifies the database schema.
+/// Scripts are typically bundled with the application and executed sequentially during version
+/// upgrades.
+///
+/// ## Topics
+///
+/// ### Properties
+/// - ``version``
+/// - ``scriptURL``
+/// - ``script``
+///
+/// ### Initializers
+/// - ``init(version:scriptURL:)``
+/// - ``init(version:byResource:extension:in:)``
 public struct Migration<Version: VersionRepresentable>: Hashable, Sendable {
     // MARK: - Properties
     
     /// The version associated with this migration step.
     public let version: Version
     
-    /// The URL pointing to the migration script (e.g., an SQL file).
+    /// The file URL of the migration script (for example, an SQL file).
     public let scriptURL: URL
     
-    /// The SQL script associated with this migration.
+    /// The migration script as a string.
     ///
-    /// This computed property reads the contents of the file at `scriptURL` and returns it as a
-    /// `SQLScript` instance. Use this to access and execute the migration's SQL commands.
+    /// Reads the contents of the file at ``scriptURL`` and trims surrounding whitespace and
+    /// newlines.
     ///
-    /// - Throws: An error if the script file cannot be read or is invalid.
-    public var script: SQLScript {
+    /// - Throws: An error if the script file cannot be read.
+    public var script: String {
         get throws {
-            try SQLScript(contentsOf: scriptURL)
+            try String(contentsOf: scriptURL)
+                .trimmingCharacters(in: .whitespacesAndNewlines)
         }
     }
     
     // MARK: - Inits
     
-    /// Creates a migration with a specified version and script URL.
+    /// Creates a migration with the specified version and script URL.
     ///
     /// - Parameters:
     ///   - version: The version this migration corresponds to.
-    ///   - scriptURL: The file URL to the migration script.
+    ///   - scriptURL: The URL of the script file to execute.
     public init(version: Version, scriptURL: URL) {
         self.version = version
         self.scriptURL = scriptURL
@@ -43,33 +54,25 @@ public struct Migration<Version: VersionRepresentable>: Hashable, Sendable {
     
     /// Creates a migration by locating a script resource in the specified bundle.
     ///
-    /// This initializer attempts to locate a script file in the provided bundle using the specified
-    /// resource `name` and optional `extension`. The `name` parameter may include or omit the file extension.
-    ///
-    /// - If `name` includes an extension (e.g., `"001_init.sql"`), pass `extension` as `nil` or an empty string.
-    /// - If `name` omits the extension (e.g., `"001_init"`), specify the extension separately
-    ///   (e.g., `"sql"`), or leave it `nil` if the file has no extension.
-    ///
-    /// - Important: Passing a name that already includes the extension while also specifying a non-`nil`
-    ///   `extension` may result in failure to locate the file.
+    /// Searches the given bundle for a script resource matching the provided name and optional file
+    /// extension.
     ///
     /// - Parameters:
     ///   - version: The version this migration corresponds to.
-    ///   - name: The resource name of the script file. May include or omit the file extension.
-    ///   - extension: The file extension, if separated from the name. Defaults to `nil`.
-    ///   - bundle: The bundle in which to search for the resource. Defaults to `.main`.
+    ///   - name: The resource name of the script file. Can include or omit its extension.
+    ///   - extension: The file extension, if separate from the name. Defaults to `nil`.
+    ///   - bundle: The bundle in which to look for the resource. Defaults to `.main`.
     ///
-    /// - Returns: A `Migration` if the resource file is found; otherwise, `nil`.
+    /// - Returns: A `Migration` instance if the resource is found; otherwise, `nil`.
     public init?(
         version: Version,
         byResource name: String,
         extension: String? = nil,
         in bundle: Bundle = .main
     ) {
-        guard let url = bundle.url(
-            forResource: name,
-            withExtension: `extension`
-        ) else { return nil }
+        guard let url = bundle.url(forResource: name, withExtension: `extension`) else {
+            return nil
+        }
         self.init(version: version, scriptURL: url)
     }
 }