SwiftDBAI: natural language queries for any SQLite database

Drop-in SwiftUI chat view, headless ChatEngine, LLM-agnostic via
AnyLanguageModel. Read-only by default with configurable allowlists.
Robust SQL parser with 63 tests. Includes demo app with GitHub stars dataset.

Tests/SwiftDBAITests/Helpers/MockLanguageModel.swift

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+// MockLanguageModel.swift
+// SwiftDBAI Tests
+//
+// A mock LanguageModel for unit tests that returns canned responses.
+
+import AnyLanguageModel
+import Foundation
+
+/// A mock language model that returns a configurable canned response.
+///
+/// Used in tests to avoid hitting a real LLM provider.
+struct MockLanguageModel: LanguageModel {
+    typealias UnavailableReason = Never
+
+    /// The text the mock will return from `respond(...)`.
+    let responseText: String
+
+    init(responseText: String = "Mock summary response.") {
+        self.responseText = responseText
+    }
+
+    func respond<Content>(
+        within session: LanguageModelSession,
+        to prompt: Prompt,
+        generating type: Content.Type,
+        includeSchemaInPrompt: Bool,
+        options: GenerationOptions
+    ) async throws -> LanguageModelSession.Response<Content> where Content: Generable {
+        let rawContent = GeneratedContent(kind: .string(responseText))
+        let content = try Content(rawContent)
+        return LanguageModelSession.Response(
+            content: content,
+            rawContent: rawContent,
+            transcriptEntries: [][...]
+        )
+    }
+
+    func streamResponse<Content>(
+        within session: LanguageModelSession,
+        to prompt: Prompt,
+        generating type: Content.Type,
+        includeSchemaInPrompt: Bool,
+        options: GenerationOptions
+    ) -> sending LanguageModelSession.ResponseStream<Content> where Content: Generable {
+        let rawContent = GeneratedContent(kind: .string(responseText))
+        let content = try! Content(rawContent)
+        return LanguageModelSession.ResponseStream(content: content, rawContent: rawContent)
+    }
+}