disks: Add new mocking types for testing and iteration

We don't ever expose these in the real world.

Signed-off-by: Ikey Doherty <[email protected]>

Author: ikeycode

crates/disks/src/disk.rs

@@ -9,7 +9,7 @@ use std::{
     path::{Path, PathBuf},
 };
 
-use crate::{mmc, nvme, partition::Partition, scsi, sysfs, virt, DEVFS_DIR};
+use crate::{mmc, mock, nvme, partition::Partition, scsi, sysfs, virt, DEVFS_DIR};
 
 /// Represents the type of disk device.
 #[derive(Debug)]
@@ -22,6 +22,8 @@ pub enum Disk {
     Nvme(nvme::Disk),
     /// Virtual disk device
     Virtual(virt::Disk),
+    /// Mock disk for testing
+    Mock(mock::MockDisk),
 }
 
 impl Deref for Disk {
@@ -34,26 +36,27 @@ impl Deref for Disk {
             Disk::Nvme(disk) => disk,
             Disk::Scsi(disk) => disk,
             Disk::Virtual(disk) => disk,
+            Disk::Mock(disk) => disk,
         }
     }
 }
 
 /// A basic disk representation containing common attributes shared by all disk types.
 /// This serves as the base structure that specific disk implementations build upon.
-#[derive(Debug)]
+#[derive(Debug, Default)]
 pub struct BasicDisk {
     /// Device name (e.g. sda, nvme0n1)
-    name: String,
+    pub(crate) name: String,
     /// Total number of sectors on the disk
-    sectors: u64,
+    pub(crate) sectors: u64,
     /// Path to the device in /dev
-    device: PathBuf,
+    pub(crate) device: PathBuf,
     /// Optional disk model name
-    model: Option<String>,
+    pub(crate) model: Option<String>,
     /// Optional disk vendor name
-    vendor: Option<String>,
+    pub(crate) vendor: Option<String>,
     /// Partitions
-    partitions: Vec<Partition>,
+    pub(crate) partitions: Vec<Partition>,
 }
 
 impl fmt::Display for Disk {
@@ -93,6 +96,11 @@ impl BasicDisk {
         &self.partitions
     }
 
+    /// Helper for MockDisk to modify partitions
+    pub(crate) fn partitions_mut(&mut self) -> &mut Vec<Partition> {
+        &mut self.partitions
+    }
+
     /// Returns the path to the disk device in dev.
     pub fn device_path(&self) -> &Path {
         &self.device

crates/disks/src/lib.rs

@@ -11,6 +11,7 @@ use std::{
 pub use disk::*;
 pub mod loopback;
 pub mod mmc;
+pub mod mock;
 pub mod nvme;
 pub mod partition;
 pub mod scsi;

crates/disks/src/mock.rs

@@ -0,0 +1,61 @@
+// SPDX-FileCopyrightText: Copyright © 2025 Serpent OS Developers
+//
+// SPDX-License-Identifier: MPL-2.0
+
+//! Mock disk device for testing.
+//!
+//! This module provides a mock disk implementation that can be used for testing
+//! disk-related functionality without requiring actual hardware devices.
+
+use std::{ops::Deref, path::PathBuf};
+
+use crate::{partition::Partition, BasicDisk};
+
+/// Represents a mock disk device.
+///
+/// This struct wraps a BasicDisk to provide mock functionality for testing.
+#[derive(Debug)]
+pub struct MockDisk(pub BasicDisk);
+
+impl Deref for MockDisk {
+    type Target = BasicDisk;
+
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+impl MockDisk {
+    /// Creates a new mock disk with the specified size in bytes
+    pub fn new(size_bytes: u64) -> Self {
+        let sectors = size_bytes / 512;
+        let disk = BasicDisk {
+            name: "mock0".to_string(),
+            sectors,
+            device: PathBuf::from("/dev/mock0"),
+            model: Some("Mock Device".to_string()),
+            vendor: Some("Mock Vendor".to_string()),
+            partitions: Vec::new(),
+        };
+        Self(disk)
+    }
+
+    /// Add a partition to the mock disk at the specified byte offsets
+    pub fn add_partition(&mut self, start_bytes: u64, end_bytes: u64) {
+        let partition_number = self.0.partitions().len() + 1;
+        let start = start_bytes / 512;
+        let end = end_bytes / 512;
+
+        let partition = Partition {
+            number: partition_number as u32,
+            start,
+            end,
+            size: end - start,
+            name: format!("mock0p{}", partition_number),
+            node: PathBuf::from("/sys/class/block/mock0/mock0p1"),
+            device: PathBuf::from(format!("/dev/mock0p{}", partition_number)),
+        };
+
+        self.0.partitions_mut().push(partition);
+    }
+}

crates/disks/src/partition.rs

@@ -9,7 +9,7 @@ use crate::{sysfs, DEVFS_DIR, SYSFS_DIR};
 
 /// Represents a partition on a disk device
 /// - Size in sectors
-#[derive(Debug)]
+#[derive(Debug, Default)]
 pub struct Partition {
     /// Name of the partition
     pub name: String,