Add explicit_write suggestions for write!s with format args

clippy_lints/src/explicit_write.rs

@@ -1,5 +1,6 @@
-use clippy_utils::diagnostics::{span_lint_and_help, span_lint_and_sugg};
+use clippy_utils::diagnostics::span_lint_and_sugg;
 use clippy_utils::macros::FormatArgsExpn;
+use clippy_utils::source::snippet_with_applicability;
 use clippy_utils::{is_expn_of, match_function_call, paths};
 use if_chain::if_chain;
 use rustc_errors::Applicability;
@@ -79,28 +80,22 @@ impl<'tcx> LateLintPass<'tcx> for ExplicitWrite {
                         "print".into(),
                     )
                 };
-                let msg = format!("use of `{}.unwrap()`", used);
-                if let [write_output] = *format_args.format_string_parts {
-                    let mut write_output = write_output.to_string();
-                    if write_output.ends_with('\n') {
-                        write_output.pop();
-                    }
-
-                    let sugg = format!("{}{}!(\"{}\")", prefix, sugg_mac, write_output.escape_default());
-                    span_lint_and_sugg(
-                        cx,
-                        EXPLICIT_WRITE,
-                        expr.span,
-                        &msg,
-                        "try this",
-                        sugg,
-                        Applicability::MachineApplicable
-                    );
-                } else {
-                    // We don't have a proper suggestion
-                    let help = format!("consider using `{}{}!` instead", prefix, sugg_mac);
-                    span_lint_and_help(cx, EXPLICIT_WRITE, expr.span, &msg, None, &help);
-                }
+                let mut applicability = Applicability::MachineApplicable;
+                let inputs_snippet = snippet_with_applicability(
+                    cx,
+                    format_args.inputs_span(),
+                    "..",
+                    &mut applicability,
+                );
+                span_lint_and_sugg(
+                    cx,
+                    EXPLICIT_WRITE,
+                    expr.span,
+                    &format!("use of `{}.unwrap()`", used),
+                    "try this",
+                    format!("{}{}!({})", prefix, sugg_mac, inputs_snippet),
+                    applicability,
+                )
             }
         }
     }

tests/ui/explicit_write.fixed

@@ -10,6 +10,12 @@ fn stderr() -> String {
     String::new()
 }
 
+macro_rules! one {
+    () => {
+        1
+    };
+}
+
 fn main() {
     // these should warn
     {
@@ -24,6 +30,12 @@ fn main() {
         // including newlines
         println!("test\ntest");
         eprintln!("test\ntest");
+
+        let value = 1;
+        eprintln!("with {}", value);
+        eprintln!("with {} {}", 2, value);
+        eprintln!("with {value}");
+        eprintln!("macro arg {}", one!());
     }
     // these should not warn, different destination
     {

tests/ui/explicit_write.rs

@@ -10,6 +10,12 @@ fn stderr() -> String {
     String::new()
 }
 
+macro_rules! one {
+    () => {
+        1
+    };
+}
+
 fn main() {
     // these should warn
     {
@@ -24,6 +30,12 @@ fn main() {
         // including newlines
         writeln!(std::io::stdout(), "test\ntest").unwrap();
         writeln!(std::io::stderr(), "test\ntest").unwrap();
+
+        let value = 1;
+        writeln!(std::io::stderr(), "with {}", value).unwrap();
+        writeln!(std::io::stderr(), "with {} {}", 2, value).unwrap();
+        writeln!(std::io::stderr(), "with {value}").unwrap();
+        writeln!(std::io::stderr(), "macro arg {}", one!()).unwrap();
     }
     // these should not warn, different destination
     {

tests/ui/explicit_write.stderr

@@ -1,52 +1,76 @@
 error: use of `write!(stdout(), ...).unwrap()`
-  --> $DIR/explicit_write.rs:17:9
+  --> $DIR/explicit_write.rs:23:9
    |
 LL |         write!(std::io::stdout(), "test").unwrap();
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `print!("test")`
    |
    = note: `-D clippy::explicit-write` implied by `-D warnings`
 
 error: use of `write!(stderr(), ...).unwrap()`
-  --> $DIR/explicit_write.rs:18:9
+  --> $DIR/explicit_write.rs:24:9
    |
 LL |         write!(std::io::stderr(), "test").unwrap();
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `eprint!("test")`
 
 error: use of `writeln!(stdout(), ...).unwrap()`
-  --> $DIR/explicit_write.rs:19:9
+  --> $DIR/explicit_write.rs:25:9
    |
 LL |         writeln!(std::io::stdout(), "test").unwrap();
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `println!("test")`
 
 error: use of `writeln!(stderr(), ...).unwrap()`
-  --> $DIR/explicit_write.rs:20:9
+  --> $DIR/explicit_write.rs:26:9
    |
 LL |         writeln!(std::io::stderr(), "test").unwrap();
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `eprintln!("test")`
 
 error: use of `stdout().write_fmt(...).unwrap()`
-  --> $DIR/explicit_write.rs:21:9
+  --> $DIR/explicit_write.rs:27:9
    |
 LL |         std::io::stdout().write_fmt(format_args!("test")).unwrap();
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `print!("test")`
 
 error: use of `stderr().write_fmt(...).unwrap()`
-  --> $DIR/explicit_write.rs:22:9
+  --> $DIR/explicit_write.rs:28:9
    |
 LL |         std::io::stderr().write_fmt(format_args!("test")).unwrap();
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `eprint!("test")`
 
 error: use of `writeln!(stdout(), ...).unwrap()`
-  --> $DIR/explicit_write.rs:25:9
+  --> $DIR/explicit_write.rs:31:9
    |
 LL |         writeln!(std::io::stdout(), "test/ntest").unwrap();
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `println!("test/ntest")`
 
 error: use of `writeln!(stderr(), ...).unwrap()`
-  --> $DIR/explicit_write.rs:26:9
+  --> $DIR/explicit_write.rs:32:9
    |
 LL |         writeln!(std::io::stderr(), "test/ntest").unwrap();
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `eprintln!("test/ntest")`
 
-error: aborting due to 8 previous errors
+error: use of `writeln!(stderr(), ...).unwrap()`
+  --> $DIR/explicit_write.rs:35:9
+   |
+LL |         writeln!(std::io::stderr(), "with {}", value).unwrap();
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `eprintln!("with {}", value)`
+
+error: use of `writeln!(stderr(), ...).unwrap()`
+  --> $DIR/explicit_write.rs:36:9
+   |
+LL |         writeln!(std::io::stderr(), "with {} {}", 2, value).unwrap();
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `eprintln!("with {} {}", 2, value)`
+
+error: use of `writeln!(stderr(), ...).unwrap()`
+  --> $DIR/explicit_write.rs:37:9
+   |
+LL |         writeln!(std::io::stderr(), "with {value}").unwrap();
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `eprintln!("with {value}")`
+
+error: use of `writeln!(stderr(), ...).unwrap()`
+  --> $DIR/explicit_write.rs:38:9
+   |
+LL |         writeln!(std::io::stderr(), "macro arg {}", one!()).unwrap();
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `eprintln!("macro arg {}", one!())`
+
+error: aborting due to 12 previous errors