bendns' repos / rust-analyzer
Unnamed repository; edit this file 'description' to name the repository.
Diffstat (limited to 'crates/ide-assists/src/handlers/generate_constant.rs')
-rw-r--r--crates/ide-assists/src/handlers/generate_constant.rs119
1 files changed, 119 insertions, 0 deletions
diff --git a/crates/ide-assists/src/handlers/generate_constant.rs b/crates/ide-assists/src/handlers/generate_constant.rs
new file mode 100644
index 0000000000..c4b759d5f3
--- /dev/null
+++ b/crates/ide-assists/src/handlers/generate_constant.rs
@@ -0,0 +1,119 @@
+use crate::assist_context::{AssistContext, Assists};
+use hir::HirDisplay;
+use ide_db::{
+ assists::{AssistId, AssistKind},
+ defs::NameRefClass,
+};
+use syntax::{
+ ast::{self, edit::IndentLevel},
+ AstNode,
+};
+
+// Assist: generate_constant
+//
+// Generate a named constant.
+//
+// ```
+// struct S { i: usize }
+// impl S { pub fn new(n: usize) {} }
+// fn main() {
+// let v = S::new(CAPA$0CITY);
+// }
+// ```
+// ->
+// ```
+// struct S { i: usize }
+// impl S { pub fn new(n: usize) {} }
+// fn main() {
+// const CAPACITY: usize = $0;
+// let v = S::new(CAPACITY);
+// }
+// ```
+
+pub(crate) fn generate_constant(acc: &mut Assists, ctx: &AssistContext) -> Option<()> {
+ let constant_token = ctx.find_node_at_offset::<ast::NameRef>()?;
+ let expr = constant_token.syntax().ancestors().find_map(ast::Expr::cast)?;
+ let statement = expr.syntax().ancestors().find_map(ast::Stmt::cast)?;
+ let ty = ctx.sema.type_of_expr(&expr)?;
+ let scope = ctx.sema.scope(statement.syntax())?;
+ let module = scope.module();
+ let type_name = ty.original().display_source_code(ctx.db(), module.into()).ok()?;
+ let indent = IndentLevel::from_node(statement.syntax());
+ if constant_token.to_string().chars().any(|it| !(it.is_uppercase() || it == '_')) {
+ cov_mark::hit!(not_constant_name);
+ return None;
+ }
+ if NameRefClass::classify(&ctx.sema, &constant_token).is_some() {
+ cov_mark::hit!(already_defined);
+ return None;
+ }
+ let target = statement.syntax().parent()?.text_range();
+ acc.add(
+ AssistId("generate_constant", AssistKind::QuickFix),
+ "Generate constant",
+ target,
+ |builder| {
+ builder.insert(
+ statement.syntax().text_range().start(),
+ format!("const {}: {} = $0;\n{}", constant_token, type_name, indent),
+ );
+ },
+ )
+}
+
+#[cfg(test)]
+mod tests {
+ use super::*;
+ use crate::tests::{check_assist, check_assist_not_applicable};
+
+ #[test]
+ fn test_trivial() {
+ check_assist(
+ generate_constant,
+ r#"struct S { i: usize }
+impl S {
+ pub fn new(n: usize) {}
+}
+fn main() {
+ let v = S::new(CAPA$0CITY);
+}"#,
+ r#"struct S { i: usize }
+impl S {
+ pub fn new(n: usize) {}
+}
+fn main() {
+ const CAPACITY: usize = $0;
+ let v = S::new(CAPACITY);
+}"#,
+ );
+ }
+ #[test]
+ fn test_wont_apply_when_defined() {
+ cov_mark::check!(already_defined);
+ check_assist_not_applicable(
+ generate_constant,
+ r#"struct S { i: usize }
+impl S {
+ pub fn new(n: usize) {}
+}
+fn main() {
+ const CAPACITY: usize = 10;
+ let v = S::new(CAPAC$0ITY);
+}"#,
+ );
+ }
+ #[test]
+ fn test_wont_apply_when_maybe_not_constant() {
+ cov_mark::check!(not_constant_name);
+ check_assist_not_applicable(
+ generate_constant,
+ r#"struct S { i: usize }
+impl S {
+ pub fn new(n: usize) {}
+}
+fn main() {
+ let v = S::new(capa$0city);
+}"#,
+ );
+ }
+}