Add tests for SVG zoom

.gitignore

@@ -7,3 +7,7 @@ DerivedData/
 .swiftpm/config/registries.json
 .swiftpm/xcode/package.xcworkspace/contents.xcworkspacedata
 .netrc
+
+.claude
+.vscode
+.zed

Tests/GeoDrawerTests/GeoDrawerSVGZoomTests.swift

@@ -0,0 +1,145 @@
+#if canImport(Testing)
+
+import Testing
+import Foundation
+#if canImport(CoreGraphics)
+import CoreGraphics
+#endif
+
+import GeoJSONKit
+@testable import GeoDrawer
+@testable import GeoProjector
+
+struct GeoDrawerSVGZoomTests {
+
+  @Test func testSVGWithoutZoom() throws {
+    let drawer = GeoDrawer(
+      size: .init(width: 400, height: 200),
+      projection: Projections.Equirectangular()
+    )
+
+    let line = GeoJSON.LineString(positions: [
+      .init(latitude: 40, longitude: -120), // West coast US
+      .init(latitude: 40, longitude: -80)   // East coast US
+    ])
+
+    let content: [GeoDrawer.Content] = [
+      .line(line, stroke: testColor(red: 1, green: 0, blue: 0), strokeWidth: 2)
+    ]
+
+    let svg = drawer.drawSVG(content)
+
+    // Just verify the basic structure and that it contains the expected line
+    #expect(svg.contains("<svg"))
+    #expect(svg.contains("<path"))
+    #expect(svg.contains("stroke=\"#FF0000\""))
+    #expect(svg.contains("d=\"M 66.7 55.6 L 111.1 55.6\""))
+  }
+
+  @Test func testSVGWithZoom() throws {
+    // Create a bounding box for North America
+    let northAmericaBbox = GeoJSON.BoundingBox(positions: [
+      .init(latitude: 10.0, longitude: -170.0),
+      .init(latitude: 70.0, longitude: -50.0)
+    ])
+
+    let drawer = GeoDrawer(
+      size: .init(width: 400, height: 200),
+      projection: Projections.Equirectangular(),
+      zoomTo: northAmericaBbox
+    )
+
+    let line = GeoJSON.LineString(positions: [
+      .init(latitude: 40, longitude: -120), // West coast US
+      .init(latitude: 40, longitude: -80)   // East coast US
+    ])
+
+    let content: [GeoDrawer.Content] = [
+      .line(line, stroke: testColor(red: 1, green: 0, blue: 0), strokeWidth: 2)
+    ]
+
+    let svg = drawer.drawSVG(content)
+
+    // With zoom to North America, the line should span a much larger portion of the width
+    // The exact coordinates will depend on the zoom calculation, but it should be noticeably different
+    // print("SVG with zoom: \(svg)")
+
+    // For now, just check that we get a valid SVG with a path element
+    #expect(svg.contains("<svg"))
+    #expect(svg.contains("<path"))
+    #expect(svg.contains("stroke=\"#FF0000\""))
+  }
+
+  @Test func testZoomActuallyChangesOutput() throws {
+    let projection = Projections.Equirectangular()
+    let size = Size(width: 400, height: 200)
+
+    // Create a bounding box for North America
+    let northAmericaBbox = GeoJSON.BoundingBox(positions: [
+      .init(latitude: 10.0, longitude: -170.0),
+      .init(latitude: 70.0, longitude: -50.0)
+    ])
+
+    let drawerNoZoom = GeoDrawer(size: size, projection: projection)
+    let drawerWithZoom = GeoDrawer(size: size, projection: projection, zoomTo: northAmericaBbox)
+
+    let line = GeoJSON.LineString(positions: [
+      .init(latitude: 40, longitude: -120), // West coast US
+      .init(latitude: 40, longitude: -80)   // East coast US
+    ])
+
+    let content: [GeoDrawer.Content] = [
+      .line(line, stroke: testColor(red: 1, green: 0, blue: 0), strokeWidth: 2)
+    ]
+
+    let svgNoZoom = drawerNoZoom.drawSVG(content)
+    let svgWithZoom = drawerWithZoom.drawSVG(content)
+
+    // print("SVG without zoom: \(svgNoZoom)")
+    // print("SVG with zoom: \(svgWithZoom)")
+
+    // The SVGs should be different if zoom is working correctly
+    #expect(svgNoZoom != svgWithZoom, "SVG output should be different when zoom is applied")
+  }
+
+  @Test func testMapBackgroundWithZoom() throws {
+    let northAmericaBbox = GeoJSON.BoundingBox(positions: [
+      .init(latitude: 10.0, longitude: -170.0),
+      .init(latitude: 70.0, longitude: -50.0)
+    ])
+
+    let drawer = GeoDrawer(
+      size: .init(width: 400, height: 200),
+      projection: Projections.Equirectangular(),
+      zoomTo: northAmericaBbox
+    )
+
+    let svg = drawer.drawSVG(
+      [],
+      mapBackground: testColor(red: 0.8, green: 0.8, blue: 1.0),
+      mapOutline: testColor(red: 0, green: 0, blue: 0)
+    )
+
+    // The map background should respect zoom settings
+    #expect(svg.contains("<svg"))
+    #expect(svg.contains("<rect"))
+    #expect(svg.contains("fill=\"#CCCCFF\""))
+    #expect(svg.contains("stroke=\"#000000\""))
+
+    // print("Map background with zoom: \(svg)")
+  }
+
+  // MARK: - Helper Methods
+
+  private func testColor(red: Double, green: Double, blue: Double, alpha: Double = 1.0)
+    -> GeoDrawer.Color
+  {
+    #if canImport(CoreGraphics)
+      return CGColor(red: red, green: green, blue: blue, alpha: alpha)
+    #else
+      return GeoDrawer.Color(red: red, green: green, blue: blue, alpha: alpha)
+    #endif
+  }
+}
+
+#endif // canImport(Testing)