Refactor suspicious_else_formatting using if_chain

This commit is contained in:
Philipp Hansch 2019-04-14 11:12:51 +02:00
parent 96c34e85c4
commit ad27e3ff9b
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GPG key ID: 82AA61CAA11397E6

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@ -3,6 +3,7 @@ use rustc::lint::{in_external_macro, EarlyContext, EarlyLintPass, LintArray, Lin
use rustc::{declare_tool_lint, lint_array};
use syntax::ast;
use syntax::ptr::P;
use if_chain::if_chain;
declare_clippy_lint! {
/// **What it does:** Checks for use of the non-existent `=*`, `=!` and `=-`
@ -146,44 +147,40 @@ fn check_assign(cx: &EarlyContext<'_>, expr: &ast::Expr) {
/// Implementation of the `SUSPICIOUS_ELSE_FORMATTING` lint for weird `else`.
fn check_else(cx: &EarlyContext<'_>, expr: &ast::Expr) {
if let Some((then, &Some(ref else_))) = unsugar_if(expr) {
if (is_block(else_) || unsugar_if(else_).is_some())
&& !differing_macro_contexts(then.span, else_.span)
&& !in_macro(then.span)
&& !in_external_macro(cx.sess, expr.span)
{
// workaround for rust-lang/rust#43081
if expr.span.lo().0 == 0 && expr.span.hi().0 == 0 {
return;
}
if_chain! {
if let Some((then, &Some(ref else_))) = unsugar_if(expr);
if is_block(else_) || unsugar_if(else_).is_some();
if !differing_macro_contexts(then.span, else_.span);
if !in_macro(then.span) && !in_external_macro(cx.sess, expr.span);
// this will be a span from the closing } of the “then” block (excluding) to
// the
// “if” of the “else if” block (excluding)
let else_span = then.span.between(else_.span);
// workaround for rust-lang/rust#43081
if expr.span.lo().0 != 0 && expr.span.hi().0 != 0;
// the snippet should look like " else \n " with maybe comments anywhere
// its bad when there is a \n after the “else”
if let Some(else_snippet) = snippet_opt(cx, else_span) {
if let Some(else_pos) = else_snippet.find("else") {
if else_snippet[else_pos..].contains('\n') {
let else_desc = if unsugar_if(else_).is_some() { "if" } else { "{..}" };
// this will be a span from the closing } of the “then” block (excluding) to
// the
// “if” of the “else if” block (excluding)
let else_span = then.span.between(else_.span);
span_note_and_lint(
cx,
SUSPICIOUS_ELSE_FORMATTING,
else_span,
&format!("this is an `else {}` but the formatting might hide it", else_desc),
else_span,
&format!(
"to remove this lint, remove the `else` or remove the new line between \
`else` and `{}`",
else_desc,
),
);
}
}
}
// the snippet should look like " else \n " with maybe comments anywhere
// its bad when there is a \n after the “else”
if let Some(else_snippet) = snippet_opt(cx, else_span);
if let Some(else_pos) = else_snippet.find("else");
if else_snippet[else_pos..].contains('\n');
let else_desc = if unsugar_if(else_).is_some() { "if" } else { "{..}" };
then {
span_note_and_lint(
cx,
SUSPICIOUS_ELSE_FORMATTING,
else_span,
&format!("this is an `else {}` but the formatting might hide it", else_desc),
else_span,
&format!(
"to remove this lint, remove the `else` or remove the new line between \
`else` and `{}`",
else_desc,
),
);
}
}
}