From c33395087da4a3fb5364c58761fa94d8ee15ca23 Mon Sep 17 00:00:00 2001
From: Ben Moss <ben@mossity.com>
Date: Tue, 22 Oct 2024 20:06:45 -0400
Subject: [PATCH 1/2] POC: pixi diff

Example:

```
pixi diff --old-lockfile <(git show HEAD~100:pixi.lock)
```
---
 src/cli/diff.rs   | 47 +++++++++++++++++++++++++++++++++++++++++++++++
 src/cli/mod.rs    |  3 +++
 src/cli/update.rs |  2 +-
 3 files changed, 51 insertions(+), 1 deletion(-)
 create mode 100644 src/cli/diff.rs

diff --git a/src/cli/diff.rs b/src/cli/diff.rs
new file mode 100644
index 000000000..32bce338e
--- /dev/null
+++ b/src/cli/diff.rs
@@ -0,0 +1,47 @@
+use std::path::{Path, PathBuf};
+
+use clap::Parser;
+use miette::IntoDiagnostic;
+use pixi_config::{self, ConfigCli};
+use rattler_lock::LockFile;
+
+use crate::{
+    cli::update::{LockFileDiff, LockFileJsonDiff},
+    Project,
+};
+
+use super::cli_config::ProjectConfig;
+
+#[derive(Parser, Debug, Default)]
+pub struct Args {
+    #[clap(flatten)]
+    pub config: ConfigCli,
+
+    #[clap(flatten)]
+    pub project_config: ProjectConfig,
+
+    #[arg(long)]
+    pub old_lockfile: PathBuf,
+}
+
+pub async fn execute(args: Args) -> miette::Result<()> {
+    let lock = LockFile::from_path(Path::new("pixi.lock")).into_diagnostic()?;
+
+    let input: Box<dyn std::io::Read + 'static> = if args.old_lockfile.as_os_str() == "-" {
+        Box::new(std::io::stdin())
+    } else {
+        Box::new(std::fs::File::open(&args.old_lockfile).into_diagnostic()?)
+    };
+
+    let old = LockFile::from_reader(input).into_diagnostic()?;
+
+    let diff = LockFileDiff::from_lock_files(&old, &lock);
+    let config = args.config;
+    let project = Project::load_or_else_discover(args.project_config.manifest_path.as_deref())?
+        .with_cli_config(config);
+    let json_diff = LockFileJsonDiff::new(&project, diff);
+    let json = serde_json::to_string_pretty(&json_diff).expect("failed to convert to json");
+    println!("{}", json);
+
+    Ok(())
+}
diff --git a/src/cli/mod.rs b/src/cli/mod.rs
index 5e6764591..df1474094 100644
--- a/src/cli/mod.rs
+++ b/src/cli/mod.rs
@@ -18,6 +18,7 @@ pub mod clean;
 pub mod cli_config;
 pub mod completion;
 pub mod config;
+pub mod diff;
 mod exec;
 pub mod global;
 pub mod has_specs;
@@ -104,6 +105,7 @@ pub enum Command {
     #[clap(visible_alias = "s")]
     Shell(shell::Args),
     ShellHook(shell_hook::Args),
+    Diff(diff::Args),
 
     // Project modification commands
     Project(project::Args),
@@ -281,6 +283,7 @@ pub async fn execute_command(command: Command) -> miette::Result<()> {
         Command::Tree(cmd) => tree::execute(cmd).await,
         Command::Update(cmd) => update::execute(cmd).await,
         Command::Exec(args) => exec::execute(args).await,
+        Command::Diff(args) => diff::execute(args).await,
     }
 }
 
diff --git a/src/cli/update.rs b/src/cli/update.rs
index 88636fa8e..76484dc73 100644
--- a/src/cli/update.rs
+++ b/src/cli/update.rs
@@ -638,7 +638,7 @@ pub struct LockFileJsonDiff {
 }
 
 impl LockFileJsonDiff {
-    fn new(project: &Project, value: LockFileDiff) -> Self {
+    pub fn new(project: &Project, value: LockFileDiff) -> Self {
         let mut environment = IndexMap::new();
 
         for (environment_name, environment_diff) in value.environment {

From 9c52d8763949bc2453a9860f7ef00bd14acbcd11 Mon Sep 17 00:00:00 2001
From: Ben Moss <ben@mossity.com>
Date: Tue, 22 Oct 2024 20:14:16 -0400
Subject: [PATCH 2/2] Clean up lockfile loading

---
 src/cli/diff.rs | 13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/src/cli/diff.rs b/src/cli/diff.rs
index 32bce338e..46b73639a 100644
--- a/src/cli/diff.rs
+++ b/src/cli/diff.rs
@@ -1,4 +1,4 @@
-use std::path::{Path, PathBuf};
+use std::path::PathBuf;
 
 use clap::Parser;
 use miette::IntoDiagnostic;
@@ -25,7 +25,9 @@ pub struct Args {
 }
 
 pub async fn execute(args: Args) -> miette::Result<()> {
-    let lock = LockFile::from_path(Path::new("pixi.lock")).into_diagnostic()?;
+    let project = Project::load_or_else_discover(args.project_config.manifest_path.as_deref())?
+        .with_cli_config(args.config);
+    let current_lockfile = LockFile::from_path(&project.lock_file_path()).into_diagnostic()?;
 
     let input: Box<dyn std::io::Read + 'static> = if args.old_lockfile.as_os_str() == "-" {
         Box::new(std::io::stdin())
@@ -33,12 +35,9 @@ pub async fn execute(args: Args) -> miette::Result<()> {
         Box::new(std::fs::File::open(&args.old_lockfile).into_diagnostic()?)
     };
 
-    let old = LockFile::from_reader(input).into_diagnostic()?;
+    let prior_lockfile = LockFile::from_reader(input).into_diagnostic()?;
 
-    let diff = LockFileDiff::from_lock_files(&old, &lock);
-    let config = args.config;
-    let project = Project::load_or_else_discover(args.project_config.manifest_path.as_deref())?
-        .with_cli_config(config);
+    let diff = LockFileDiff::from_lock_files(&prior_lockfile, &current_lockfile);
     let json_diff = LockFileJsonDiff::new(&project, diff);
     let json = serde_json::to_string_pretty(&json_diff).expect("failed to convert to json");
     println!("{}", json);