Lints and suggestions for the Nix programming language
refactor(collapsible_let_in): use let-else and try-expression
+36
-35
+36
-35
lib/src/lints/collapsible_let_in.rs
+36
-35
lib/src/lints/collapsible_let_in.rs
···
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impl Rule for CollapsibleLetIn {
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fn validate(&self, node: &SyntaxElement, _sess: &SessionInfo) -> Option<Report> {
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if let NodeOrToken::Node(node) = node
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&& let Some(let_in_expr) = LetIn::cast(node.clone())
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&& let Some(body) = let_in_expr.body()
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&& LetIn::cast(body.clone()).is_some()
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{
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let first_annotation = node.text_range();
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let first_message = "This `let in` expression contains a nested `let in` expression";
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let NodeOrToken::Node(node) = node else {
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return None;
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};
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let second_annotation = body.text_range();
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let second_message = "This `let in` expression is nested";
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let let_in_expr = LetIn::cast(node.clone())?;
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let body = let_in_expr.body()?;
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+
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LetIn::cast(body.clone())?;
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let replacement_at = {
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let start = body
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.siblings_with_tokens(Direction::Prev)
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.find(|elem| elem.kind() == SyntaxKind::TOKEN_IN)?
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.text_range()
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.start();
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let end = body
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.descendants_with_tokens()
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.find(|elem| elem.kind() == SyntaxKind::TOKEN_LET)?
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.text_range()
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.end();
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TextRange::new(start, end)
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};
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let replacement = make::empty().node().clone();
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let first_annotation = node.text_range();
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let first_message = "This `let in` expression contains a nested `let in` expression";
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+
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let second_annotation = body.text_range();
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let second_message = "This `let in` expression is nested";
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+
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let replacement_at = {
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let start = body
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+
.siblings_with_tokens(Direction::Prev)
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+
.find(|elem| elem.kind() == SyntaxKind::TOKEN_IN)?
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+
.text_range()
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.start();
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let end = body
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+
.descendants_with_tokens()
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.find(|elem| elem.kind() == SyntaxKind::TOKEN_LET)?
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.text_range()
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.end();
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TextRange::new(start, end)
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};
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let replacement = make::empty().node().clone();
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Some(
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self.report()
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.diagnostic(first_annotation, first_message)
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.suggest(
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second_annotation,
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second_message,
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Suggestion::new(replacement_at, replacement),
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),
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)
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} else {
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None
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}
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Some(
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self.report()
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.diagnostic(first_annotation, first_message)
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.suggest(
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second_annotation,
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second_message,
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Suggestion::new(replacement_at, replacement),
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),
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)
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}
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}