Fix expect_fun_call
lint suggestions
This commit corrects some bad suggestions produced by the `expect_fun_call` lint and enables `rust-fix` checking on the tests. Addresses #3630
This commit is contained in:
parent
99c5388ce6
commit
5284b95a06
@ -1148,28 +1148,6 @@ fn lint_or_fun_call(cx: &LateContext<'_, '_>, expr: &hir::Expr, method_span: Spa
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/// Checks for the `EXPECT_FUN_CALL` lint.
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fn lint_expect_fun_call(cx: &LateContext<'_, '_>, expr: &hir::Expr, method_span: Span, name: &str, args: &[hir::Expr]) {
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fn extract_format_args(arg: &hir::Expr) -> Option<(&hir::Expr, &hir::Expr)> {
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let arg = match &arg.node {
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hir::ExprKind::AddrOf(_, expr) => expr,
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hir::ExprKind::MethodCall(method_name, _, args)
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if method_name.ident.name == "as_str" || method_name.ident.name == "as_ref" =>
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{
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&args[0]
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},
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_ => arg,
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};
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if let hir::ExprKind::Call(ref inner_fun, ref inner_args) = arg.node {
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if is_expn_of(inner_fun.span, "format").is_some() && inner_args.len() == 1 {
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if let hir::ExprKind::Call(_, format_args) = &inner_args[0].node {
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return Some((&format_args[0], &format_args[1]));
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}
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}
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}
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None
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}
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fn generate_format_arg_snippet(
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cx: &LateContext<'_, '_>,
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a: &hir::Expr,
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@ -1189,93 +1167,115 @@ fn lint_expect_fun_call(cx: &LateContext<'_, '_>, expr: &hir::Expr, method_span:
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unreachable!()
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}
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fn check_general_case(
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cx: &LateContext<'_, '_>,
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name: &str,
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method_span: Span,
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self_expr: &hir::Expr,
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arg: &hir::Expr,
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span: Span,
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) {
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fn is_call(node: &hir::ExprKind) -> bool {
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match node {
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hir::ExprKind::AddrOf(_, expr) => {
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is_call(&expr.node)
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},
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hir::ExprKind::Call(..)
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| hir::ExprKind::MethodCall(..)
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// These variants are debatable or require further examination
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| hir::ExprKind::If(..)
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| hir::ExprKind::Match(..)
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| hir::ExprKind::Block{ .. } => true,
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_ => false,
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fn is_call(node: &hir::ExprKind) -> bool {
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match node {
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hir::ExprKind::AddrOf(_, expr) => {
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is_call(&expr.node)
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},
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hir::ExprKind::Call(..)
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| hir::ExprKind::MethodCall(..)
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// These variants are debatable or require further examination
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| hir::ExprKind::If(..)
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| hir::ExprKind::Match(..)
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| hir::ExprKind::Block{ .. } => true,
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_ => false,
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}
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}
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if args.len() != 2 || name != "expect" || !is_call(&args[1].node) {
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return;
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}
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let receiver_type = cx.tables.expr_ty(&args[0]);
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let closure_args = if match_type(cx, receiver_type, &paths::OPTION) {
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"||"
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} else if match_type(cx, receiver_type, &paths::RESULT) {
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"|_|"
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} else {
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return;
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};
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// Strip off `&`, `as_ref()` and `as_str()` until we're left with either a `String` or `&str`
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// which we call `arg_root`.
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let mut arg_root = &args[1];
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loop {
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arg_root = match &arg_root.node {
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hir::ExprKind::AddrOf(_, expr) => expr,
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hir::ExprKind::MethodCall(method_name, _, call_args) => {
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if call_args.len() == 1
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&& (method_name.ident.name == "as_str" || method_name.ident.name == "as_ref")
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&& {
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let arg_type = cx.tables.expr_ty(&call_args[0]);
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let base_type = walk_ptrs_ty(arg_type);
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base_type.sty == ty::Str || match_type(cx, base_type, &paths::STRING)
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}
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{
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&call_args[0]
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} else {
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break;
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}
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},
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_ => break,
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};
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}
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let span_replace_word = method_span.with_hi(expr.span.hi());
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let mut applicability = Applicability::MachineApplicable;
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//Special handling for `format!` as arg_root
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if let hir::ExprKind::Call(ref inner_fun, ref inner_args) = arg_root.node {
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if is_expn_of(inner_fun.span, "format").is_some() && inner_args.len() == 1 {
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if let hir::ExprKind::Call(_, format_args) = &inner_args[0].node {
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let fmt_spec = &format_args[0];
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let fmt_args = &format_args[1];
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let mut applicability = Applicability::MachineApplicable;
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let mut args = vec![snippet(cx, fmt_spec.span, "..").into_owned()];
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args.extend(generate_format_arg_snippet(cx, fmt_args, &mut applicability));
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let sugg = args.join(", ");
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span_lint_and_sugg(
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cx,
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EXPECT_FUN_CALL,
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span_replace_word,
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&format!("use of `{}` followed by a function call", name),
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"try this",
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format!("unwrap_or_else({} panic!({}))", closure_args, sugg),
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applicability,
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);
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return;
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}
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}
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if name != "expect" {
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return;
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}
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let self_type = cx.tables.expr_ty(self_expr);
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let known_types = &[&paths::OPTION, &paths::RESULT];
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// if not a known type, return early
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if known_types.iter().all(|&k| !match_type(cx, self_type, k)) {
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return;
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}
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if !is_call(&arg.node) {
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return;
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}
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let closure = if match_type(cx, self_type, &paths::OPTION) {
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"||"
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} else {
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"|_|"
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};
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let span_replace_word = method_span.with_hi(span.hi());
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if let Some((fmt_spec, fmt_args)) = extract_format_args(arg) {
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let mut applicability = Applicability::MachineApplicable;
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let mut args = vec![snippet(cx, fmt_spec.span, "..").into_owned()];
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args.extend(generate_format_arg_snippet(cx, fmt_args, &mut applicability));
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let sugg = args.join(", ");
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span_lint_and_sugg(
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cx,
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EXPECT_FUN_CALL,
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span_replace_word,
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&format!("use of `{}` followed by a function call", name),
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"try this",
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format!("unwrap_or_else({} panic!({}))", closure, sugg),
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applicability,
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);
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return;
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}
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let mut applicability = Applicability::MachineApplicable;
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let sugg: Cow<'_, _> = snippet_with_applicability(cx, arg.span, "..", &mut applicability);
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span_lint_and_sugg(
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cx,
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EXPECT_FUN_CALL,
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span_replace_word,
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&format!("use of `{}` followed by a function call", name),
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"try this",
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format!("unwrap_or_else({} {{ let msg = {}; panic!(msg) }}))", closure, sugg),
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applicability,
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);
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}
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if args.len() == 2 {
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match args[1].node {
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hir::ExprKind::Lit(_) => {},
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_ => check_general_case(cx, name, method_span, &args[0], &args[1], expr.span),
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// If root_arg is `&'static str` or `String` we can use it directly in the `panic!` call otherwise
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// we must use `to_string` to convert it.
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let mut arg_root_snippet: Cow<'_, _> = snippet_with_applicability(cx, arg_root.span, "..", &mut applicability);
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let arg_root_ty = cx.tables.expr_ty(arg_root);
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let mut requires_conv = !match_type(cx, arg_root_ty, &paths::STRING);
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if let ty::Ref(ty::ReStatic, ty, ..) = arg_root_ty.sty {
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if ty.sty == ty::Str {
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requires_conv = false;
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}
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};
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if requires_conv {
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arg_root_snippet.to_mut().push_str(".to_string()");
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}
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span_lint_and_sugg(
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cx,
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EXPECT_FUN_CALL,
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span_replace_word,
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&format!("use of `{}` followed by a function call", name),
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"try this",
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format!("unwrap_or_else({} {{ panic!({}) }})", closure_args, arg_root_snippet),
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applicability,
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);
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}
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/// Checks for the `CLONE_ON_COPY` lint.
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84
tests/ui/expect_fun_call.fixed
Normal file
84
tests/ui/expect_fun_call.fixed
Normal file
@ -0,0 +1,84 @@
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// run-rustfix
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#![warn(clippy::expect_fun_call)]
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/// Checks implementation of the `EXPECT_FUN_CALL` lint
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fn main() {
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struct Foo;
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impl Foo {
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fn new() -> Self {
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Foo
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}
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fn expect(&self, msg: &str) {
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panic!("{}", msg)
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}
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}
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let with_some = Some("value");
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with_some.expect("error");
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let with_none: Option<i32> = None;
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with_none.expect("error");
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let error_code = 123_i32;
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let with_none_and_format: Option<i32> = None;
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with_none_and_format.unwrap_or_else(|| panic!("Error {}: fake error", error_code));
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let with_none_and_as_str: Option<i32> = None;
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with_none_and_as_str.unwrap_or_else(|| panic!("Error {}: fake error", error_code));
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let with_ok: Result<(), ()> = Ok(());
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with_ok.expect("error");
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let with_err: Result<(), ()> = Err(());
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with_err.expect("error");
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let error_code = 123_i32;
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let with_err_and_format: Result<(), ()> = Err(());
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with_err_and_format.unwrap_or_else(|_| panic!("Error {}: fake error", error_code));
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let with_err_and_as_str: Result<(), ()> = Err(());
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with_err_and_as_str.unwrap_or_else(|_| panic!("Error {}: fake error", error_code));
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let with_dummy_type = Foo::new();
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with_dummy_type.expect("another test string");
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let with_dummy_type_and_format = Foo::new();
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with_dummy_type_and_format.expect(&format!("Error {}: fake error", error_code));
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let with_dummy_type_and_as_str = Foo::new();
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with_dummy_type_and_as_str.expect(format!("Error {}: fake error", error_code).as_str());
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//Issue #2937
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Some("foo").unwrap_or_else(|| panic!("{} {}", 1, 2));
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//Issue #2979 - this should not lint
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{
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let msg = "bar";
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Some("foo").expect(msg);
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}
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{
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fn get_string() -> String {
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"foo".to_string()
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}
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fn get_static_str() -> &'static str {
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"foo"
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}
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fn get_non_static_str(_: &u32) -> &str {
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"foo"
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}
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Some("foo").unwrap_or_else(|| { panic!(get_string()) });
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Some("foo").unwrap_or_else(|| { panic!(get_string()) });
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Some("foo").unwrap_or_else(|| { panic!(get_string()) });
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Some("foo").unwrap_or_else(|| { panic!(get_static_str()) });
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Some("foo").unwrap_or_else(|| { panic!(get_non_static_str(&0).to_string()) });
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}
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}
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@ -1,9 +1,10 @@
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// run-rustfix
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#![warn(clippy::expect_fun_call)]
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#![allow(clippy::useless_format)]
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/// Checks implementation of the `EXPECT_FUN_CALL` lint
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fn expect_fun_call() {
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fn main() {
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struct Foo;
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impl Foo {
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@ -51,14 +52,33 @@ fn expect_fun_call() {
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let with_dummy_type_and_as_str = Foo::new();
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with_dummy_type_and_as_str.expect(format!("Error {}: fake error", error_code).as_str());
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//Issue #2979 - this should not lint
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let msg = "bar";
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Some("foo").expect(msg);
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Some("foo").expect({ &format!("error") });
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Some("foo").expect(format!("error").as_ref());
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//Issue #2937
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Some("foo").expect(format!("{} {}", 1, 2).as_ref());
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}
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fn main() {}
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//Issue #2979 - this should not lint
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{
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let msg = "bar";
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Some("foo").expect(msg);
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}
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{
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fn get_string() -> String {
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"foo".to_string()
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}
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fn get_static_str() -> &'static str {
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"foo"
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}
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fn get_non_static_str(_: &u32) -> &str {
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"foo"
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}
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Some("foo").expect(&get_string());
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Some("foo").expect(get_string().as_ref());
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Some("foo").expect(get_string().as_str());
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Some("foo").expect(get_static_str());
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Some("foo").expect(get_non_static_str(&0));
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}
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}
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@ -1,5 +1,5 @@
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error: use of `expect` followed by a function call
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--> $DIR/expect_fun_call.rs:27:26
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--> $DIR/expect_fun_call.rs:28:26
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LL | with_none_and_format.expect(&format!("Error {}: fake error", error_code));
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| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `unwrap_or_else(|| panic!("Error {}: fake error", error_code))`
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@ -7,40 +7,58 @@ LL | with_none_and_format.expect(&format!("Error {}: fake error", error_code
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= note: `-D clippy::expect-fun-call` implied by `-D warnings`
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error: use of `expect` followed by a function call
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--> $DIR/expect_fun_call.rs:30:26
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--> $DIR/expect_fun_call.rs:31:26
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|
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LL | with_none_and_as_str.expect(format!("Error {}: fake error", error_code).as_str());
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| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `unwrap_or_else(|| panic!("Error {}: fake error", error_code))`
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error: use of `expect` followed by a function call
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--> $DIR/expect_fun_call.rs:40:25
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--> $DIR/expect_fun_call.rs:41:25
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|
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LL | with_err_and_format.expect(&format!("Error {}: fake error", error_code));
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| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `unwrap_or_else(|_| panic!("Error {}: fake error", error_code))`
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error: use of `expect` followed by a function call
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--> $DIR/expect_fun_call.rs:43:25
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--> $DIR/expect_fun_call.rs:44:25
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|
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LL | with_err_and_as_str.expect(format!("Error {}: fake error", error_code).as_str());
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| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `unwrap_or_else(|_| panic!("Error {}: fake error", error_code))`
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error: use of `expect` followed by a function call
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--> $DIR/expect_fun_call.rs:58:17
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|
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LL | Some("foo").expect({ &format!("error") });
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| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `unwrap_or_else(|| { let msg = { &format!("error") }; panic!(msg) }))`
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error: use of `expect` followed by a function call
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--> $DIR/expect_fun_call.rs:59:17
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|
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LL | Some("foo").expect(format!("error").as_ref());
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| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `unwrap_or_else(|| panic!("error"))`
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error: use of `expect` followed by a function call
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--> $DIR/expect_fun_call.rs:61:17
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--> $DIR/expect_fun_call.rs:56:17
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|
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LL | Some("foo").expect(format!("{} {}", 1, 2).as_ref());
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| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `unwrap_or_else(|| panic!("{} {}", 1, 2))`
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error: aborting due to 7 previous errors
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error: use of `expect` followed by a function call
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--> $DIR/expect_fun_call.rs:77:21
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|
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LL | Some("foo").expect(&get_string());
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| ^^^^^^^^^^^^^^^^^^^^^ help: try this: `unwrap_or_else(|| { panic!(get_string()) })`
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error: use of `expect` followed by a function call
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--> $DIR/expect_fun_call.rs:78:21
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|
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LL | Some("foo").expect(get_string().as_ref());
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| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `unwrap_or_else(|| { panic!(get_string()) })`
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error: use of `expect` followed by a function call
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--> $DIR/expect_fun_call.rs:79:21
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|
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LL | Some("foo").expect(get_string().as_str());
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| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `unwrap_or_else(|| { panic!(get_string()) })`
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error: use of `expect` followed by a function call
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--> $DIR/expect_fun_call.rs:81:21
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|
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LL | Some("foo").expect(get_static_str());
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| ^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `unwrap_or_else(|| { panic!(get_static_str()) })`
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|
||||
error: use of `expect` followed by a function call
|
||||
--> $DIR/expect_fun_call.rs:82:21
|
||||
|
|
||||
LL | Some("foo").expect(get_non_static_str(&0));
|
||||
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `unwrap_or_else(|| { panic!(get_non_static_str(&0).to_string()) })`
|
||||
|
||||
error: aborting due to 10 previous errors
|
||||
|
||||
|
Loading…
Reference in New Issue
Block a user