Files
ruff/src/pyflakes/fixes.rs
2022-11-04 12:04:14 -04:00

141 lines
4.3 KiB
Rust

use anyhow::Result;
use libcst_native::{Codegen, ImportNames, NameOrAttribute, SmallStatement, Statement};
use rustpython_ast::Stmt;
use crate::ast::types::Range;
use crate::autofix::{helpers, Fix};
use crate::cst::helpers::compose_module_path;
use crate::cst::matchers::match_module;
use crate::source_code_locator::SourceCodeLocator;
/// Generate a Fix to remove any unused imports from an `import` statement.
pub fn remove_unused_imports(
locator: &SourceCodeLocator,
full_names: &[&str],
stmt: &Stmt,
parent: Option<&Stmt>,
deleted: &[&Stmt],
) -> Result<Fix> {
let module_text = locator.slice_source_code_range(&Range::from_located(stmt));
let mut tree = match_module(&module_text)?;
let body = if let Some(Statement::Simple(body)) = tree.body.first_mut() {
body
} else {
return Err(anyhow::anyhow!("Expected node to be: Statement::Simple"));
};
let body = if let Some(SmallStatement::Import(body)) = body.body.first_mut() {
body
} else {
return Err(anyhow::anyhow!(
"Expected node to be: SmallStatement::ImportFrom"
));
};
let aliases = &mut body.names;
// Preserve the trailing comma (or not) from the last entry.
let trailing_comma = aliases.last().and_then(|alias| alias.comma.clone());
// Identify unused imports from within the `import`.
let mut removable = vec![];
for (index, alias) in aliases.iter().enumerate() {
if full_names.contains(&compose_module_path(&alias.name).as_str()) {
removable.push(index);
}
}
// TODO(charlie): This is quadratic.
for index in removable.iter().rev() {
aliases.remove(*index);
}
if let Some(alias) = aliases.last_mut() {
alias.comma = trailing_comma;
}
if aliases.is_empty() {
helpers::remove_stmt(stmt, parent, deleted)
} else {
let mut state = Default::default();
tree.codegen(&mut state);
Ok(Fix::replacement(
state.to_string(),
stmt.location,
stmt.end_location.unwrap(),
))
}
}
/// Generate a Fix to remove any unused imports from an `import from` statement.
pub fn remove_unused_import_froms(
locator: &SourceCodeLocator,
full_names: &[&str],
stmt: &Stmt,
parent: Option<&Stmt>,
deleted: &[&Stmt],
) -> Result<Fix> {
let module_text = locator.slice_source_code_range(&Range::from_located(stmt));
let mut tree = match_module(&module_text)?;
let body = if let Some(Statement::Simple(body)) = tree.body.first_mut() {
body
} else {
return Err(anyhow::anyhow!("Expected node to be: Statement::Simple"));
};
let body = if let Some(SmallStatement::ImportFrom(body)) = body.body.first_mut() {
body
} else {
return Err(anyhow::anyhow!(
"Expected node to be: SmallStatement::ImportFrom"
));
};
let aliases = if let ImportNames::Aliases(aliases) = &mut body.names {
aliases
} else {
return Err(anyhow::anyhow!("Expected node to be: Aliases"));
};
// Preserve the trailing comma (or not) from the last entry.
let trailing_comma = aliases.last().and_then(|alias| alias.comma.clone());
// Identify unused imports from within the `import from`.
let mut removable = vec![];
for (index, alias) in aliases.iter().enumerate() {
if let NameOrAttribute::N(name) = &alias.name {
let import_name = name.value.to_string();
let full_name = body
.module
.as_ref()
.map(compose_module_path)
.map(|module_name| format!("{module_name}.{import_name}"))
.unwrap_or(import_name);
if full_names.contains(&full_name.as_str()) {
removable.push(index);
}
}
}
// TODO(charlie): This is quadratic.
for index in removable.iter().rev() {
aliases.remove(*index);
}
if let Some(alias) = aliases.last_mut() {
alias.comma = trailing_comma;
}
if aliases.is_empty() {
helpers::remove_stmt(stmt, parent, deleted)
} else {
let mut state = Default::default();
tree.codegen(&mut state);
Ok(Fix::replacement(
state.to_string(),
stmt.location,
stmt.end_location.unwrap(),
))
}
}