rust/crates/ra_ide_api/src/call_info.rs

408 lines
10 KiB
Rust

use test_utils::tested_by;
use ra_db::SourceDatabase;
use ra_syntax::{
AstNode, SyntaxNode, TextUnit, TextRange,
SyntaxKind::FN_DEF,
ast::{self, ArgListOwner},
algo::find_node_at_offset,
};
use hir::Docs;
use crate::{FilePosition, CallInfo, db::RootDatabase};
/// Computes parameter information for the given call expression.
pub(crate) fn call_info(db: &RootDatabase, position: FilePosition) -> Option<CallInfo> {
let file = db.parse(position.file_id);
let syntax = file.syntax();
// Find the calling expression and it's NameRef
let calling_node = FnCallNode::with_node(syntax, position.offset)?;
let name_ref = calling_node.name_ref()?;
// Resolve the function's NameRef (NOTE: this isn't entirely accurate).
let file_symbols = db.index_resolve(name_ref);
let symbol = file_symbols
.into_iter()
.find(|it| it.ptr.kind() == FN_DEF)?;
let fn_file = db.parse(symbol.file_id);
let fn_def = symbol.ptr.to_node(&fn_file);
let fn_def = ast::FnDef::cast(fn_def).unwrap();
let function = hir::source_binder::function_from_source(db, symbol.file_id, fn_def)?;
let mut call_info = CallInfo::new(db, function, fn_def)?;
// If we have a calling expression let's find which argument we are on
let num_params = call_info.parameters.len();
let has_self = fn_def.param_list().and_then(|l| l.self_param()).is_some();
if num_params == 1 {
if !has_self {
call_info.active_parameter = Some(0);
}
} else if num_params > 1 {
// Count how many parameters into the call we are.
// TODO: This is best effort for now and should be fixed at some point.
// It may be better to see where we are in the arg_list and then check
// where offset is in that list (or beyond).
// Revisit this after we get documentation comments in.
if let Some(ref arg_list) = calling_node.arg_list() {
let arg_list_range = arg_list.syntax().range();
if !arg_list_range.contains_inclusive(position.offset) {
tested_by!(call_info_bad_offset);
return None;
}
let start = arg_list_range.start();
let range_search = TextRange::from_to(start, position.offset);
let mut commas: usize = arg_list
.syntax()
.text()
.slice(range_search)
.to_string()
.matches(',')
.count();
// If we have a method call eat the first param since it's just self.
if has_self {
commas += 1;
}
call_info.active_parameter = Some(commas);
}
}
Some(call_info)
}
enum FnCallNode<'a> {
CallExpr(&'a ast::CallExpr),
MethodCallExpr(&'a ast::MethodCallExpr),
}
impl<'a> FnCallNode<'a> {
pub fn with_node(syntax: &'a SyntaxNode, offset: TextUnit) -> Option<FnCallNode<'a>> {
if let Some(expr) = find_node_at_offset::<ast::CallExpr>(syntax, offset) {
return Some(FnCallNode::CallExpr(expr));
}
if let Some(expr) = find_node_at_offset::<ast::MethodCallExpr>(syntax, offset) {
return Some(FnCallNode::MethodCallExpr(expr));
}
None
}
pub fn name_ref(&self) -> Option<&'a ast::NameRef> {
match *self {
FnCallNode::CallExpr(call_expr) => Some(match call_expr.expr()?.kind() {
ast::ExprKind::PathExpr(path_expr) => path_expr.path()?.segment()?.name_ref()?,
_ => return None,
}),
FnCallNode::MethodCallExpr(call_expr) => call_expr
.syntax()
.children()
.filter_map(ast::NameRef::cast)
.nth(0),
}
}
pub fn arg_list(&self) -> Option<&'a ast::ArgList> {
match *self {
FnCallNode::CallExpr(expr) => expr.arg_list(),
FnCallNode::MethodCallExpr(expr) => expr.arg_list(),
}
}
}
impl CallInfo {
fn new(db: &RootDatabase, function: hir::Function, node: &ast::FnDef) -> Option<Self> {
let label = crate::completion::function_label(node)?;
let doc = function.docs(db);
Some(CallInfo {
parameters: param_list(node),
label,
doc,
active_parameter: None,
})
}
}
fn param_list(node: &ast::FnDef) -> Vec<String> {
let mut res = vec![];
if let Some(param_list) = node.param_list() {
if let Some(self_param) = param_list.self_param() {
res.push(self_param.syntax().text().to_string())
}
// Maybe use param.pat here? See if we can just extract the name?
//res.extend(param_list.params().map(|p| p.syntax().text().to_string()));
res.extend(
param_list
.params()
.filter_map(|p| p.pat())
.map(|pat| pat.syntax().text().to_string()),
);
}
res
}
#[cfg(test)]
mod tests {
use test_utils::covers;
use crate::mock_analysis::single_file_with_position;
use super::*;
fn call_info(text: &str) -> CallInfo {
let (analysis, position) = single_file_with_position(text);
analysis.call_info(position).unwrap().unwrap()
}
#[test]
fn test_fn_signature_two_args_first() {
let info = call_info(
r#"fn foo(x: u32, y: u32) -> u32 {x + y}
fn bar() { foo(<|>3, ); }"#,
);
assert_eq!(info.parameters, vec!("x".to_string(), "y".to_string()));
assert_eq!(info.active_parameter, Some(0));
}
#[test]
fn test_fn_signature_two_args_second() {
let info = call_info(
r#"fn foo(x: u32, y: u32) -> u32 {x + y}
fn bar() { foo(3, <|>); }"#,
);
assert_eq!(info.parameters, vec!("x".to_string(), "y".to_string()));
assert_eq!(info.active_parameter, Some(1));
}
#[test]
fn test_fn_signature_for_impl() {
let info = call_info(
r#"struct F; impl F { pub fn new() { F{}} }
fn bar() {let _ : F = F::new(<|>);}"#,
);
assert_eq!(info.parameters, Vec::<String>::new());
assert_eq!(info.active_parameter, None);
}
#[test]
fn test_fn_signature_for_method_self() {
let info = call_info(
r#"struct F;
impl F {
pub fn new() -> F{
F{}
}
pub fn do_it(&self) {}
}
fn bar() {
let f : F = F::new();
f.do_it(<|>);
}"#,
);
assert_eq!(info.parameters, vec!["&self".to_string()]);
assert_eq!(info.active_parameter, None);
}
#[test]
fn test_fn_signature_for_method_with_arg() {
let info = call_info(
r#"struct F;
impl F {
pub fn new() -> F{
F{}
}
pub fn do_it(&self, x: i32) {}
}
fn bar() {
let f : F = F::new();
f.do_it(<|>);
}"#,
);
assert_eq!(info.parameters, vec!["&self".to_string(), "x".to_string()]);
assert_eq!(info.active_parameter, Some(1));
}
#[test]
fn test_fn_signature_with_docs_simple() {
let info = call_info(
r#"
/// test
// non-doc-comment
fn foo(j: u32) -> u32 {
j
}
fn bar() {
let _ = foo(<|>);
}
"#,
);
assert_eq!(info.parameters, vec!["j".to_string()]);
assert_eq!(info.active_parameter, Some(0));
assert_eq!(info.label, "fn foo(j: u32) -> u32".to_string());
assert_eq!(info.doc.map(|it| it.into()), Some("test".to_string()));
}
#[test]
fn test_fn_signature_with_docs() {
let info = call_info(
r#"
/// Adds one to the number given.
///
/// # Examples
///
/// ```
/// let five = 5;
///
/// assert_eq!(6, my_crate::add_one(5));
/// ```
pub fn add_one(x: i32) -> i32 {
x + 1
}
pub fn do() {
add_one(<|>
}"#,
);
assert_eq!(info.parameters, vec!["x".to_string()]);
assert_eq!(info.active_parameter, Some(0));
assert_eq!(info.label, "pub fn add_one(x: i32) -> i32".to_string());
assert_eq!(
info.doc.map(|it| it.into()),
Some(
r#"Adds one to the number given.
# Examples
```
let five = 5;
assert_eq!(6, my_crate::add_one(5));
```"#
.to_string()
)
);
}
#[test]
fn test_fn_signature_with_docs_impl() {
let info = call_info(
r#"
struct addr;
impl addr {
/// Adds one to the number given.
///
/// # Examples
///
/// ```
/// let five = 5;
///
/// assert_eq!(6, my_crate::add_one(5));
/// ```
pub fn add_one(x: i32) -> i32 {
x + 1
}
}
pub fn do_it() {
addr {};
addr::add_one(<|>);
}"#,
);
assert_eq!(info.parameters, vec!["x".to_string()]);
assert_eq!(info.active_parameter, Some(0));
assert_eq!(info.label, "pub fn add_one(x: i32) -> i32".to_string());
assert_eq!(
info.doc.map(|it| it.into()),
Some(
r#"Adds one to the number given.
# Examples
```
let five = 5;
assert_eq!(6, my_crate::add_one(5));
```"#
.to_string()
)
);
}
#[test]
fn test_fn_signature_with_docs_from_actix() {
let info = call_info(
r#"
pub trait WriteHandler<E>
where
Self: Actor,
Self::Context: ActorContext,
{
/// Method is called when writer emits error.
///
/// If this method returns `ErrorAction::Continue` writer processing
/// continues otherwise stream processing stops.
fn error(&mut self, err: E, ctx: &mut Self::Context) -> Running {
Running::Stop
}
/// Method is called when writer finishes.
///
/// By default this method stops actor's `Context`.
fn finished(&mut self, ctx: &mut Self::Context) {
ctx.stop()
}
}
pub fn foo() {
WriteHandler r;
r.finished(<|>);
}
"#,
);
assert_eq!(
info.parameters,
vec!["&mut self".to_string(), "ctx".to_string()]
);
assert_eq!(info.active_parameter, Some(1));
assert_eq!(
info.doc.map(|it| it.into()),
Some(
r#"Method is called when writer finishes.
By default this method stops actor's `Context`."#
.to_string()
)
);
}
#[test]
fn call_info_bad_offset() {
covers!(call_info_bad_offset);
let (analysis, position) = single_file_with_position(
r#"fn foo(x: u32, y: u32) -> u32 {x + y}
fn bar() { foo <|> (3, ); }"#,
);
let call_info = analysis.call_info(position).unwrap();
assert!(call_info.is_none());
}
}