Properly throw errors

.swiftlint.yml

@@ -1,5 +1,6 @@
 disabled_rules:
   - trailing_comma
+  - todo
 excluded:
   - .build
   - .git

Sources/SwiftH3/H3Coordinate.swift

@@ -27,7 +27,7 @@ public struct H3Coordinate {
 }
 
 extension H3Coordinate: Equatable {
-    
+
     public static func == (lhs: H3Coordinate, rhs: H3Coordinate) -> Bool {
         lhs.lat == rhs.lat && lhs.lon == rhs.lon
     }

Sources/SwiftH3/H3Index.swift

@@ -117,8 +117,7 @@ extension H3Index {
             gridDiskError = gridDisk(value, ringK, ptr.baseAddress)
         }
         if gridDiskError.code != .success {
-            // TODO: throw
-            return []
+            throw gridDiskError.code
         }
 
         return indices.map { H3Index($0) }
@@ -161,12 +160,11 @@ extension H3Index {
     /// - Parameter resolution: The resolution for the parent
     /// - Returns: The parent index at that resolution.
     ///            Can be nil if invalid
-    public func children(at resolution: Int) -> [H3Index] {
+    public func children(at resolution: Int) throws -> [H3Index] {
         var maxChildren: Int64 = 0
         let maxChildrenError = cellToChildrenSize(value, Int32(resolution), &maxChildren)
         if maxChildrenError.code != .success {
-            // TODO: Throw
-            return []
+            throw maxChildrenError.code
         }
 
         var error: H3Error
@@ -176,8 +174,7 @@ extension H3Index {
         )
         error = cellToChildren(value, Int32(resolution), &children)
         if error.code != .success {
-            // TODO: throw
-            return []
+            throw error.code
         }
 
         return children

Tests/SwiftH3Tests/H3IndexTests.swift

@@ -91,13 +91,13 @@ final class H3IndexTests: XCTestCase {
 
     func testChildren() {
         let index = H3Index(0x8a2a10766d87fff)
-        XCTAssertEqual(index.children(at: 9), [])
+        XCTAssertThrowsError(try index.children(at: 9), "Resolution is lower than index resolution")
 
         let expectedRes11 = [
             0x8b2a10766d80fff, 0x8b2a10766d81fff, 0x8b2a10766d82fff, 0x8b2a10766d83fff,
             0x8b2a10766d84fff, 0x8b2a10766d85fff, 0x8b2a10766d86fff
         ].map { H3Index($0) }
-        XCTAssertEqual(index.children(at: 11), expectedRes11)
+        XCTAssertEqual(try index.children(at: 11), expectedRes11)
 
         let expectedRes12 = [
             0x8c2a10766d801ff, 0x8c2a10766d803ff, 0x8c2a10766d805ff, 0x8c2a10766d807ff,
@@ -114,7 +114,7 @@ final class H3IndexTests: XCTestCase {
             0x8c2a10766d865ff, 0x8c2a10766d867ff, 0x8c2a10766d869ff, 0x8c2a10766d86bff,
             0x8c2a10766d86dff
         ].map { H3Index($0) }
-        XCTAssertEqual(index.children(at: 12), expectedRes12)
+        XCTAssertEqual(try index.children(at: 12), expectedRes12)
     }
 
     func testCenterChild() {
@@ -142,7 +142,21 @@ final class H3IndexTests: XCTestCase {
         ])
 
         let cells = H3Index.polygonToCells(polygon: polygon, resolution: 9)
-        XCTAssertEqual(cells, [0x892a100da4bffff, 0x892a1072d2fffff, 0x892a1072993ffff, 0x892a100da4fffff, 0x892a100da7bffff, 0x892a1072997ffff, 0x892a1072987ffff, 0x892a10729b3ffff, 0x892a100da43ffff, 0x892a1072d27ffff, 0x892a100da5bffff, 0x892a10729b7ffff, 0x892a10729a3ffff].map(H3Index.init))
+        XCTAssertEqual(cells, [
+            0x892a100da4bffff,
+            0x892a1072d2fffff,
+            0x892a1072993ffff,
+            0x892a100da4fffff,
+            0x892a100da7bffff,
+            0x892a1072997ffff,
+            0x892a1072987ffff,
+            0x892a10729b3ffff,
+            0x892a100da43ffff,
+            0x892a1072d27ffff,
+            0x892a100da5bffff,
+            0x892a10729b7ffff,
+            0x892a10729a3ffff
+        ].map(H3Index.init))
     }
 
     static var allTests = [