Add a puffin remove command (#120)

crates/puffin-cli/src/commands/mod.rs

@@ -5,6 +5,7 @@ pub(crate) use add::add;
 pub(crate) use clean::clean;
 pub(crate) use compile::compile;
 pub(crate) use freeze::freeze;
+pub(crate) use remove::remove;
 pub(crate) use sync::{sync, SyncFlags};
 pub(crate) use uninstall::uninstall;
 pub(crate) use venv::venv;
@@ -13,6 +14,7 @@ mod add;
 mod clean;
 mod compile;
 mod freeze;
+mod remove;
 mod reporters;
 mod sync;
 mod uninstall;

crates/puffin-cli/src/commands/remove.rs

@@ -0,0 +1,73 @@
+use std::path::PathBuf;
+
+use anyhow::Result;
+use miette::{Diagnostic, IntoDiagnostic};
+use thiserror::Error;
+use tracing::info;
+
+use puffin_workspace::WorkspaceError;
+
+use crate::commands::ExitStatus;
+use crate::printer::Printer;
+
+/// Remove a dependency from the workspace.
+#[allow(clippy::unnecessary_wraps)]
+pub(crate) fn remove(name: &str, _printer: Printer) -> Result<ExitStatus> {
+    match remove_impl(name) {
+        Ok(status) => Ok(status),
+        Err(err) => {
+            #[allow(clippy::print_stderr)]
+            {
+                eprint!("{err:?}");
+            }
+            Ok(ExitStatus::Failure)
+        }
+    }
+}
+
+#[derive(Error, Debug, Diagnostic)]
+enum RemoveError {
+    #[error(
+        "Could not find a `pyproject.toml` file in the current directory or any of its parents"
+    )]
+    #[diagnostic(code(puffin::remove::workspace_not_found))]
+    WorkspaceNotFound,
+
+    #[error("Failed to parse `pyproject.toml` at: `{0}`")]
+    #[diagnostic(code(puffin::remove::parse_error))]
+    ParseError(PathBuf, #[source] WorkspaceError),
+
+    #[error("Failed to write `pyproject.toml` to: `{0}`")]
+    #[diagnostic(code(puffin::remove::write_error))]
+    WriteError(PathBuf, #[source] WorkspaceError),
+
+    #[error("Failed to remove `{0}` from `pyproject.toml`")]
+    #[diagnostic(code(puffin::remove::parse_error))]
+    RemovalError(String, #[source] WorkspaceError),
+}
+
+fn remove_impl(name: &str) -> miette::Result<ExitStatus> {
+    // Locate the workspace.
+    let cwd = std::env::current_dir().into_diagnostic()?;
+    let Some(workspace_root) = puffin_workspace::find_pyproject_toml(cwd) else {
+        return Err(RemoveError::WorkspaceNotFound.into());
+    };
+
+    info!("Found workspace at: {}", workspace_root.display());
+
+    // Parse the manifest.
+    let mut manifest = puffin_workspace::Workspace::try_from(workspace_root.as_path())
+        .map_err(|err| RemoveError::ParseError(workspace_root.clone(), err))?;
+
+    // Remove the dependency.
+    manifest
+        .remove_dependency(name)
+        .map_err(|err| RemoveError::RemovalError(name.to_string(), err))?;
+
+    // Write the manifest back to disk.
+    manifest
+        .save(&workspace_root)
+        .map_err(|err| RemoveError::WriteError(workspace_root.clone(), err))?;
+
+    Ok(ExitStatus::Success)
+}

crates/puffin-cli/src/commands/venv.rs

@@ -1,7 +1,7 @@
 use std::fmt::Write;
 use std::path::Path;
 
-use anyhow::{Context, Result};
+use anyhow::Result;
 use colored::Colorize;
 use fs_err::tokio as fs;
 
@@ -29,8 +29,8 @@ pub(crate) async fn venv(
     )?;
 
     // If the path already exists, remove it.
-    fs::remove_file(path).await.context("Foo")?;
-    fs::remove_dir_all(path).await?;
+    fs::remove_file(path).await.ok();
+    fs::remove_dir_all(path).await.ok();
 
     writeln!(
         printer,

crates/puffin-cli/src/main.rs

@@ -47,6 +47,8 @@ enum Commands {
     Venv(VenvArgs),
     /// Add a dependency to the workspace.
     Add(AddArgs),
+    /// Remove a dependency from the workspace.
+    Remove(RemoveArgs),
 }
 
 #[derive(Args)]
@@ -87,7 +89,13 @@ struct VenvArgs {
 
 #[derive(Args)]
 struct AddArgs {
-    /// The name of the package to add.
+    /// The name of the package to add (e.g., `Django==4.2.6`).
+    name: String,
+}
+
+#[derive(Args)]
+struct RemoveArgs {
+    /// The name of the package to remove (e.g., `Django`).
     name: String,
 }
 
@@ -162,6 +170,7 @@ async fn main() -> ExitCode {
         }
         Commands::Venv(args) => commands::venv(&args.name, args.python.as_deref(), printer).await,
         Commands::Add(args) => commands::add(&args.name, printer),
+        Commands::Remove(args) => commands::remove(&args.name, printer),
     };
 
     match result {

crates/puffin-workspace/src/error.rs

@@ -14,4 +14,13 @@ pub enum WorkspaceError {
 
     #[error(transparent)]
     InvalidRequirement(#[from] pep508_rs::Pep508Error),
+
+    #[error("no `[project]` table found in `pyproject.toml`")]
+    MissingProjectTable,
+
+    #[error("no `[project.dependencies]` array found in `pyproject.toml`")]
+    MissingProjectDependenciesArray,
+
+    #[error("unable to find package: `{0}`")]
+    MissingPackage(String),
 }

crates/puffin-workspace/src/toml.rs

@@ -1,5 +1,10 @@
 /// Reformat a TOML array to use multiline format.
 pub(crate) fn format_multiline_array(dependencies: &mut toml_edit::Array) {
+    if dependencies.is_empty() {
+        dependencies.set_trailing("");
+        return;
+    }
+
     for item in dependencies.iter_mut() {
         let decor = item.decor_mut();
         let mut prefix = String::new();

crates/puffin-workspace/src/workspace.rs

@@ -76,9 +76,7 @@ impl Workspace {
             return;
         };
 
-        // TODO(charlie): Awkward `drop` pattern required to work around destructors, apparently.
-        let mut iter = dependencies.iter();
-        let index = iter.position(|item| {
+        let index = dependencies.iter().position(|item| {
             let Some(item) = item.as_str() else {
                 return false;
             };
@@ -90,7 +88,6 @@ impl Workspace {
             PackageName::normalize(&requirement.requirement.name)
                 == PackageName::normalize(existing.name)
         });
-        drop(iter);
 
         if let Some(index) = index {
             dependencies.replace(index, requirement.given_name);
@@ -101,6 +98,45 @@ impl Workspace {
         format_multiline_array(dependencies);
     }
 
+    /// Remove a dependency from the workspace.
+    pub fn remove_dependency(&mut self, name: &str) -> Result<(), WorkspaceError> {
+        let Some(project) = self
+            .document
+            .get_mut("project")
+            .map(|project| project.as_table_mut().unwrap())
+        else {
+            return Err(WorkspaceError::MissingProjectTable);
+        };
+
+        let Some(dependencies) = project
+            .get_mut("dependencies")
+            .map(|dependencies| dependencies.as_array_mut().unwrap())
+        else {
+            return Err(WorkspaceError::MissingProjectDependenciesArray);
+        };
+
+        let index = dependencies.iter().position(|item| {
+            let Some(item) = item.as_str() else {
+                return false;
+            };
+
+            let Ok(existing) = Requirement::from_str(item) else {
+                return false;
+            };
+
+            PackageName::normalize(name) == PackageName::normalize(existing.name)
+        });
+
+        let Some(index) = index else {
+            return Err(WorkspaceError::MissingPackage(name.to_string()));
+        };
+
+        dependencies.remove(index);
+        format_multiline_array(dependencies);
+
+        Ok(())
+    }
+
     /// Save the workspace to disk.
     pub fn save(&self, path: impl AsRef<Path>) -> Result<(), WorkspaceError> {
         let file = fs::File::create(path.as_ref())?;