Show disk usage in image list

Sources/ContainerCommands/Image/ImageResource+ListDisplayable.swift

@@ -17,10 +17,11 @@
 import ContainerAPIClient
 import ContainerResource
 import ContainerizationOCI
+import Foundation
 
 extension ImageResource: ListDisplayable {
     public static var tableHeader: [String] {
-        ["NAME", "TAG", "DIGEST"]
+        ["NAME", "TAG", "DIGEST", "DISK USAGE"]
     }
 
     public var tableRow: [String] {
@@ -30,10 +31,23 @@ extension ImageResource: ListDisplayable {
             reference?.name ?? displayReference,
             reference?.tag ?? "<none>",
             Utility.trimDigest(digest: configuration.descriptor.digest),
+            formattedDiskUsage,
         ]
     }
 
     public var quietValue: String {
         name
     }
+
+    private var diskUsage: Int64 {
+        variants
+            // Skip attestation manifests, which use the `unknown/unknown` platform.
+            .filter { !($0.platform.os == "unknown" && $0.platform.architecture == "unknown") }
+            .reduce(0) { $0 + $1.size }
+    }
+
+    private var formattedDiskUsage: String {
+        let formatter = ByteCountFormatter()
+        return formatter.string(fromByteCount: diskUsage)
+    }
 }

Tests/ContainerCommandsTests/ListFormattingTests.swift

@@ -15,6 +15,7 @@
 //===----------------------------------------------------------------------===//
 
 import ContainerResource
+import ContainerizationOCI
 import Foundation
 import Testing
 
@@ -273,6 +274,58 @@ struct NetworkResourceDisplayTests {
     }
 }
 
+// MARK: - ImageResource ListDisplayable conformance tests
+
+struct ImageResourceDisplayTests {
+    @Test
+    func tableHeaderIncludesDiskUsage() {
+        #expect(ImageResource.tableHeader == ["NAME", "TAG", "DIGEST", "DISK USAGE"])
+    }
+
+    @Test
+    func tableRowIncludesDiskUsage() {
+        let resource = makeImageResource(variants: [
+            .init(platform: try! Platform(from: "linux/arm64"), digest: "sha256:manifest1", size: 1024, config: makeImageConfig()),
+            .init(platform: try! Platform(from: "linux/amd64"), digest: "sha256:manifest2", size: 2048, config: makeImageConfig()),
+        ])
+
+        #expect(resource.tableRow == ["alpine", "latest", "abcdef123456", formattedByteCount(3072)])
+    }
+
+    @Test
+    func diskUsageSkipsUnknownPlatformAttestations() {
+        let resource = makeImageResource(variants: [
+            .init(platform: try! Platform(from: "linux/arm64"), digest: "sha256:manifest1", size: 1024, config: makeImageConfig()),
+            .init(platform: Platform(arch: "unknown", os: "unknown"), digest: "sha256:attestation", size: 2048, config: makeImageConfig()),
+        ])
+
+        #expect(resource.tableRow.last == formattedByteCount(1024))
+    }
+
+    private func makeImageResource(variants: [ImageResource.Variant]) -> ImageResource {
+        ImageResource(
+            configuration: .init(
+                description: .init(
+                    reference: "docker.io/library/alpine:latest",
+                    descriptor: .init(mediaType: "application/vnd.oci.image.index.v1+json", digest: "sha256:abcdef123456", size: 42)
+                ),
+                creationDate: Date(timeIntervalSince1970: 0)
+            ),
+            variants: variants,
+            displayReference: "alpine:latest"
+        )
+    }
+
+    private func makeImageConfig() -> ContainerizationOCI.Image {
+        .init(architecture: "arm64", os: "linux", rootfs: .init(type: "layers", diffIDs: []))
+    }
+
+    private func formattedByteCount(_ value: Int64) -> String {
+        let formatter = ByteCountFormatter()
+        return formatter.string(fromByteCount: value)
+    }
+}
+
 // MARK: - ListFormat tests
 
 struct ListFormatTests {

docs/command-reference.md

@@ -532,7 +532,7 @@ No options.
 
 ### `container image list (ls)`
 
-Lists local images. Verbose output provides additional details such as image ID, creation time and full size; formatted output provides the same data in machine-readable form.
+Lists local images with name, tag, digest, and disk usage. Verbose output provides additional details such as image ID, creation time and full size; formatted output provides the same data in machine-readable form.
 
 **Usage**