Ignore if_then_panic clippy lint

error: only a `panic!` in `if`-then statement
      --> serde_derive/src/internals/ctxt.rs:58:9
       |
    58 | /         if !thread::panicking() && self.errors.borrow().is_some() {
    59 | |             panic!("forgot to check for errors");
    60 | |         }
       | |_________^ help: try: `assert!(!!thread::panicking() && self.errors.borrow().is_some(), "forgot to check for errors");`
       |
    note: the lint level is defined here
      --> serde_derive/src/lib.rs:18:9
       |
    18 | #![deny(clippy::all, clippy::pedantic)]
       |         ^^^^^^^^^^^
       = note: `#[deny(clippy::if_then_panic)]` implied by `#[deny(clippy::all)]`
       = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#if_then_panic

    error: only a `panic!` in `if`-then statement
       --> serde_test/src/assert.rs:73:5
        |
    73  | /     if ser.remaining() > 0 {
    74  | |         panic!("{} remaining tokens", ser.remaining());
    75  | |     }
        | |_____^ help: try: `assert!(!ser.remaining() > 0, "{} remaining tokens", ser.remaining());`
        |
    note: the lint level is defined here
       --> serde_test/src/lib.rs:149:44
        |
    149 | #![cfg_attr(feature = "cargo-clippy", deny(clippy, clippy_pedantic))]
        |                                            ^^^^^^
        = note: `#[deny(clippy::if_then_panic)]` implied by `#[deny(clippy::all)]`
        = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#if_then_panic

    error: only a `panic!` in `if`-then statement
       --> serde_test/src/assert.rs:126:5
        |
    126 | /     if ser.remaining() > 0 {
    127 | |         panic!("{} remaining tokens", ser.remaining());
    128 | |     }
        | |_____^ help: try: `assert!(!ser.remaining() > 0, "{} remaining tokens", ser.remaining());`
        |
        = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#if_then_panic

    error: only a `panic!` in `if`-then statement
       --> serde_test/src/assert.rs:166:5
        |
    166 | /     if de.remaining() > 0 {
    167 | |         panic!("{} remaining tokens", de.remaining());
    168 | |     }
        | |_____^ help: try: `assert!(!de.remaining() > 0, "{} remaining tokens", de.remaining());`
        |
        = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#if_then_panic

    error: only a `panic!` in `if`-then statement
       --> serde_test/src/assert.rs:180:5
        |
    180 | /     if de.remaining() > 0 {
    181 | |         panic!("{} remaining tokens", de.remaining());
    182 | |     }
        | |_____^ help: try: `assert!(!de.remaining() > 0, "{} remaining tokens", de.remaining());`
        |
        = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#if_then_panic

    error: only a `panic!` in `if`-then statement
       --> serde_test/src/assert.rs:220:5
        |
    220 | /     if de.remaining() > 0 {
    221 | |         panic!("{} remaining tokens", de.remaining());
    222 | |     }
        | |_____^ help: try: `assert!(!de.remaining() > 0, "{} remaining tokens", de.remaining());`
        |
        = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#if_then_panic

    error: only a `panic!` in `if`-then statement
        --> test_suite/tests/test_de.rs:1349:9
         |
    1349 | /         if de.remaining() > 0 {
    1350 | |             panic!("{} remaining tokens", de.remaining());
    1351 | |         }
         | |_________^ help: try: `assert!(!de.remaining() > 0, "{} remaining tokens", de.remaining());`
         |
         = note: `-D clippy::if-then-panic` implied by `-D clippy::all`
         = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#if_then_panic

serde_derive/src/lib.rs

@@ -24,6 +24,7 @@
     // clippy bug: https://github.com/rust-lang/rust-clippy/issues/7575
     clippy::collapsible_match,
     clippy::enum_variant_names,
+    clippy::if_then_panic,
     // clippy bug: https://github.com/rust-lang/rust-clippy/issues/6797
     clippy::manual_map,
     clippy::match_like_matches_macro,

serde_derive_internals/lib.rs

@@ -6,6 +6,7 @@
     clippy::cognitive_complexity,
     // clippy bug: https://github.com/rust-lang/rust-clippy/issues/7575
     clippy::collapsible_match,
+    clippy::if_then_panic,
     // clippy bug: https://github.com/rust-lang/rust-clippy/issues/6797
     clippy::manual_map,
     clippy::missing_panics_doc,

serde_test/src/lib.rs

@@ -155,6 +155,7 @@
     allow(
         cloned_instead_of_copied,
         empty_line_after_outer_attr,
+        if_then_panic,
         missing_docs_in_private_items,
         missing_panics_doc,
         module_name_repetitions,

test_suite/tests/test_de.rs

@@ -1,4 +1,8 @@
-#![allow(clippy::decimal_literal_representation, clippy::unreadable_literal)]
+#![allow(
+    clippy::decimal_literal_representation,
+    clippy::if_then_panic,
+    clippy::unreadable_literal
+)]
 #![cfg_attr(feature = "unstable", feature(never_type))]
 
 use std::collections::{BTreeMap, BTreeSet, HashMap, HashSet};