Replace if with option, add detail for each env variable completion

Author: btwotwo

crates/ide-completion/src/completions/env_vars.rs

@@ -1,8 +1,8 @@
 //! Completes environment variables defined by Cargo (https://doc.rust-lang.org/cargo/reference/environment-variables.html)
+use ide_db::syntax_helpers::node_ext::get_outer_macro_name;
+use syntax::ast::{self, IsString};
 
-use syntax::{ast, AstToken, AstNode, TextRange, TextSize};
-
-use crate::{context::CompletionContext, CompletionItem, CompletionItemKind};
+use crate::{CompletionItem, CompletionItemKind};
 
 use super::Completions;
 const CARGO_DEFINED_VARS: &[(&str, &str)] = &[
@@ -29,34 +29,27 @@ const CARGO_DEFINED_VARS: &[(&str, &str)] = &[
 
 pub(crate) fn complete_cargo_env_vars(
     acc: &mut Completions,
-    ctx: &CompletionContext<'_>,
-    original: &ast::String
-) {
-    if !is_env_macro(original) {
-        return;
-    }
-
-    let start = ctx.original_token.text_range().start() + TextSize::from(1);
-    let cursor = ctx.position.offset;
-
-    CompletionItem::new(CompletionItemKind::Binding, TextRange::new(start, cursor), "CARGO").add_to(acc);
+    expanded: &ast::String,
+) -> Option<()> {
+    guard_env_macro(expanded)?;
+    let range = expanded.text_range_between_quotes()?;
+
+    CARGO_DEFINED_VARS.iter().for_each(|(var, detail)| {
+        let mut item = CompletionItem::new(CompletionItemKind::Keyword, range, *var);
+        item.detail(*detail);
+        item.add_to(acc);
+    });
+
+    Some(())
 }
 
-fn is_env_macro(string: &ast::String) -> bool {
-    //todo: replace copypaste from format_string with separate function
-    (|| {
-        let macro_call = string.syntax().parent_ancestors().find_map(ast::MacroCall::cast)?;
-        let name = macro_call.path()?.segment()?.name_ref()?;
-
-        if !matches!(name.text().as_str(), 
-        "env" | "option_env") {
-            return None;
-        }
-
+fn guard_env_macro(string: &ast::String) -> Option<()> {
+    let name = get_outer_macro_name(string)?;
+    if !matches!(name.text().as_str(), "env" | "option_env") {
+        return None;
+    }
 
-        Some(())
-    })()
-    .is_some()
+    Some(())
 }
 
 #[cfg(test)]
@@ -112,4 +105,4 @@ mod tests {
         let completions = completion_list(fixture);
         assert!(completions.is_empty(), "Completions weren't empty: {}", completions);
     }
-}
+}