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|
use test_utils::tested_by;
use ra_db::SourceDatabase;
use ra_syntax::{
AstNode, SyntaxNode, TextUnit,
SyntaxKind::FN_DEF,
ast::{self, ArgListOwner},
algo::find_node_at_offset,
};
use hir::Docs;
use crate::{FilePosition, CallInfo, FunctionSignature, 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 = crate::symbol_index::index_resolve(db, 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.
if let Some(arg_list) = calling_node.arg_list() {
// Number of arguments specified at the call site
let num_args_at_callsite = arg_list.args().count();
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 mut param = std::cmp::min(
num_args_at_callsite,
arg_list
.args()
.take_while(|arg| arg.syntax().range().end() < position.offset)
.count(),
);
// If we are in a method account for `self`
if has_self {
param = param + 1;
}
call_info.active_parameter = Some(param);
}
}
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 doc = function.docs(db);
let signature = FunctionSignature::from(node).with_doc_opt(doc);
Some(CallInfo { signature, active_parameter: None })
}
fn parameters(&self) -> &[String] {
&self.signature.parameters
}
}
#[cfg(test)]
mod tests {
use test_utils::covers;
use crate::mock_analysis::single_file_with_position;
use super::*;
// These are only used when testing
impl CallInfo {
fn doc(&self) -> Option<hir::Documentation> {
self.signature.doc.clone()
}
fn label(&self) -> String {
self.signature.to_string()
}
}
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(), ["x: u32", "y: u32"]);
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(), ["x: u32", "y: u32"]);
assert_eq!(info.active_parameter, Some(1));
}
#[test]
fn test_fn_signature_two_args_empty() {
let info = call_info(
r#"fn foo(x: u32, y: u32) -> u32 {x + y}
fn bar() { foo(<|>); }"#,
);
assert_eq!(info.parameters(), ["x: u32", "y: u32"]);
assert_eq!(info.active_parameter, Some(0));
}
#[test]
fn test_fn_signature_two_args_first_generics() {
let info = call_info(
r#"fn foo<T, U: Copy + Display>(x: T, y: U) -> u32 where T: Copy + Display, U: Debug {x + y}
fn bar() { foo(<|>3, ); }"#,
);
assert_eq!(info.parameters(), ["x: T", "y: U"]);
assert_eq!(
info.label(),
r#"
fn foo<T, U: Copy + Display>(x: T, y: U) -> u32
where T: Copy + Display,
U: Debug
"#
.trim()
);
assert_eq!(info.active_parameter, Some(0));
}
#[test]
fn test_fn_signature_no_params() {
let info = call_info(
r#"fn foo<T>() -> T where T: Copy + Display {}
fn bar() { foo(<|>); }"#,
);
assert!(info.parameters().is_empty());
assert_eq!(
info.label(),
r#"
fn foo<T>() -> T
where T: Copy + Display
"#
.trim()
);
assert!(info.active_parameter.is_none());
}
#[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!(info.parameters().is_empty());
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(), ["&self"]);
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(), ["&self", "x: i32"]);
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(), ["j: u32"]);
assert_eq!(info.active_parameter, Some(0));
assert_eq!(info.label(), "fn foo(j: u32) -> u32");
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(), ["x: i32"]);
assert_eq!(info.active_parameter, Some(0));
assert_eq!(info.label(), "pub fn add_one(x: i32) -> i32");
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(), ["x: i32"]);
assert_eq!(info.active_parameter, Some(0));
assert_eq!(info.label(), "pub fn add_one(x: i32) -> i32");
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(), ["&mut self", "ctx: &mut Self::Context"]);
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());
}
}
|