Name assist handlers

1 files changed, 150 insertions, 0 deletions

diff --git a/crates/ra_assists/src/handlers/remove_dbg.rs b/crates/ra_assists/src/handlers/remove_dbg.rs
new file mode 100644
index 000000000..5085649b4
--- /dev/null
+++ b/crates/ra_assists/src/handlers/remove_dbg.rs
@@ -0,0 +1,150 @@
+use ra_syntax::{
+    ast::{self, AstNode},
+    TextUnit, T,
+};
+
+use crate::{Assist, AssistCtx, AssistId};
+
+// Assist: remove_dbg
+//
+// Removes `dbg!()` macro call.
+//
+// ```
+// fn main() {
+//     <|>dbg!(92);
+// }
+// ```
+// ->
+// ```
+// fn main() {
+//     92;
+// }
+// ```
+pub(crate) fn remove_dbg(ctx: AssistCtx) -> Option<Assist> {
+    let macro_call = ctx.find_node_at_offset::<ast::MacroCall>()?;
+
+    if !is_valid_macrocall(&macro_call, "dbg")? {
+        return None;
+    }
+
+    let macro_range = macro_call.syntax().text_range();
+
+    // If the cursor is inside the macro call, we'll try to maintain the cursor
+    // position by subtracting the length of dbg!( from the start of the file
+    // range, otherwise we'll default to using the start of the macro call
+    let cursor_pos = {
+        let file_range = ctx.frange.range;
+
+        let offset_start = file_range
+            .start()
+            .checked_sub(macro_range.start())
+            .unwrap_or_else(|| TextUnit::from(0));
+
+        let dbg_size = TextUnit::of_str("dbg!(");
+
+        if offset_start > dbg_size {
+            file_range.start() - dbg_size
+        } else {
+            macro_range.start()
+        }
+    };
+
+    let macro_content = {
+        let macro_args = macro_call.token_tree()?.syntax().clone();
+
+        let text = macro_args.text();
+        let without_parens = TextUnit::of_char('(')..text.len() - TextUnit::of_char(')');
+        text.slice(without_parens).to_string()
+    };
+
+    ctx.add_assist(AssistId("remove_dbg"), "Remove dbg!()", |edit| {
+        edit.target(macro_call.syntax().text_range());
+        edit.replace(macro_range, macro_content);
+        edit.set_cursor(cursor_pos);
+    })
+}
+
+/// Verifies that the given macro_call actually matches the given name
+/// and contains proper ending tokens
+fn is_valid_macrocall(macro_call: &ast::MacroCall, macro_name: &str) -> Option<bool> {
+    let path = macro_call.path()?;
+    let name_ref = path.segment()?.name_ref()?;
+
+    // Make sure it is actually a dbg-macro call, dbg followed by !
+    let excl = path.syntax().next_sibling_or_token()?;
+
+    if name_ref.text() != macro_name || excl.kind() != T![!] {
+        return None;
+    }
+
+    let node = macro_call.token_tree()?.syntax().clone();
+    let first_child = node.first_child_or_token()?;
+    let last_child = node.last_child_or_token()?;
+
+    match (first_child.kind(), last_child.kind()) {
+        (T!['('], T![')']) | (T!['['], T![']']) | (T!['{'], T!['}']) => Some(true),
+        _ => Some(false),
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::helpers::{check_assist, check_assist_not_applicable, check_assist_target};
+
+    #[test]
+    fn test_remove_dbg() {
+        check_assist(remove_dbg, "<|>dbg!(1 + 1)", "<|>1 + 1");
+
+        check_assist(remove_dbg, "dbg!<|>((1 + 1))", "<|>(1 + 1)");
+
+        check_assist(remove_dbg, "dbg!(1 <|>+ 1)", "1 <|>+ 1");
+
+        check_assist(remove_dbg, "let _ = <|>dbg!(1 + 1)", "let _ = <|>1 + 1");
+
+        check_assist(
+            remove_dbg,
+            "
+fn foo(n: usize) {
+    if let Some(_) = dbg!(n.<|>checked_sub(4)) {
+        // ...
+    }
+}
+",
+            "
+fn foo(n: usize) {
+    if let Some(_) = n.<|>checked_sub(4) {
+        // ...
+    }
+}
+",
+        );
+    }
+    #[test]
+    fn test_remove_dbg_with_brackets_and_braces() {
+        check_assist(remove_dbg, "dbg![<|>1 + 1]", "<|>1 + 1");
+        check_assist(remove_dbg, "dbg!{<|>1 + 1}", "<|>1 + 1");
+    }
+
+    #[test]
+    fn test_remove_dbg_not_applicable() {
+        check_assist_not_applicable(remove_dbg, "<|>vec![1, 2, 3]");
+        check_assist_not_applicable(remove_dbg, "<|>dbg(5, 6, 7)");
+        check_assist_not_applicable(remove_dbg, "<|>dbg!(5, 6, 7");
+    }
+
+    #[test]
+    fn remove_dbg_target() {
+        check_assist_target(
+            remove_dbg,
+            "
+fn foo(n: usize) {
+    if let Some(_) = dbg!(n.<|>checked_sub(4)) {
+        // ...
+    }
+}
+",
+            "dbg!(n.checked_sub(4))",
+        );
+    }
+}