rust/crates/test-utils/src/fixture.rs

509 lines
16 KiB
Rust

//! Defines `Fixture` -- a convenient way to describe the initial state of
//! rust-analyzer database from a single string.
//!
//! Fixtures are strings containing rust source code with optional metadata.
//! A fixture without metadata is parsed into a single source file.
//! Use this to test functionality local to one file.
//!
//! Simple Example:
//! ```
//! r#"
//! fn main() {
//! println!("Hello World")
//! }
//! "#
//! ```
//!
//! Metadata can be added to a fixture after a `//-` comment.
//! The basic form is specifying filenames,
//! which is also how to define multiple files in a single test fixture
//!
//! Example using two files in the same crate:
//! ```
//! "
//! //- /main.rs
//! mod foo;
//! fn main() {
//! foo::bar();
//! }
//!
//! //- /foo.rs
//! pub fn bar() {}
//! "
//! ```
//!
//! Example using two crates with one file each, with one crate depending on the other:
//! ```
//! r#"
//! //- /main.rs crate:a deps:b
//! fn main() {
//! b::foo();
//! }
//! //- /lib.rs crate:b
//! pub fn b() {
//! println!("Hello World")
//! }
//! "#
//! ```
//!
//! Metadata allows specifying all settings and variables
//! that are available in a real rust project. See [`Fixture`]
//! for the syntax.
//!
//! Example using some available metadata:
//! ```
//! "
//! //- /lib.rs crate:foo deps:bar,baz cfg:foo=a,bar=b env:OUTDIR=path/to,OTHER=foo
//! fn insert_source_code_here() {}
//! "
//! ```
use std::iter;
use rustc_hash::FxHashMap;
use stdx::trim_indent;
#[derive(Debug, Eq, PartialEq)]
pub struct Fixture {
/// Specifies the path for this file. It must start with "/".
pub path: String,
/// Defines a new crate and make this file its root module.
///
/// Version and repository URL of the crate can optionally be specified; if
/// either one is specified, the other must also be specified.
///
/// Syntax:
/// - `crate:my_awesome_lib`
/// - `crate:my_awesome_lib@0.0.1,https://example.com/repo.git`
pub krate: Option<String>,
/// Specifies dependencies of this crate. This must be used with `crate` meta.
///
/// Syntax: `deps:hir-def,ide-assists`
pub deps: Vec<String>,
/// Limits crates in the extern prelude. The set of crate names must be a
/// subset of `deps`. This must be used with `crate` meta.
///
/// If this is not specified, all the dependencies will be in the extern prelude.
///
/// Syntax: `extern-prelude:hir-def,ide-assists`
pub extern_prelude: Option<Vec<String>>,
/// Specifies configuration options to be enabled. Options may have associated
/// values.
///
/// Syntax: `cfg:test,dbg=false,opt_level=2`
pub cfgs: Vec<(String, Option<String>)>,
/// Specifies the edition of this crate. This must be used with `crate` meta. If
/// this is not specified, ([`base_db::input::Edition::CURRENT`]) will be used.
/// This must be used with `crate` meta.
///
/// Syntax: `edition:2021`
pub edition: Option<String>,
/// Specifies environment variables.
///
/// Syntax: `env:PATH=/bin,RUST_LOG=debug`
pub env: FxHashMap<String, String>,
/// Introduces a new [source root](base_db::input::SourceRoot). This file **and
/// the following files** will belong the new source root. This must be used
/// with `crate` meta.
///
/// Use this if you want to test something that uses `SourceRoot::is_library()`
/// to check editability.
///
/// Note that files before the first fixture with `new_source_root` meta will
/// belong to an implicitly defined local source root.
///
/// Syntax:
/// - `new_source_root:library`
/// - `new_source_root:local`
pub introduce_new_source_root: Option<String>,
/// Explicitly declares this crate as a library outside current workspace. This
/// must be used with `crate` meta.
///
/// This is implied if this file belongs to a library source root.
///
/// Use this if you want to test something that checks if a crate is a workspace
/// member via [`CrateOrigin`](base_db::input::CrateOrigin).
///
/// Syntax: `library`
pub library: bool,
/// Actual file contents. All meta comments are stripped.
pub text: String,
}
pub struct MiniCore {
activated_flags: Vec<String>,
valid_flags: Vec<String>,
}
pub struct FixtureWithProjectMeta {
pub fixture: Vec<Fixture>,
pub mini_core: Option<MiniCore>,
pub proc_macro_names: Vec<String>,
pub toolchain: Option<String>,
/// Specifies LLVM data layout to be used.
///
/// You probably don't want to manually specify this. See LLVM manual for the
/// syntax, if you must: https://llvm.org/docs/LangRef.html#data-layout
pub target_data_layout: String,
}
impl FixtureWithProjectMeta {
/// Parses text which looks like this:
///
/// ```not_rust
/// //- some meta
/// line 1
/// line 2
/// //- other meta
/// ```
///
/// Fixture can also start with a proc_macros and minicore declaration (in that order):
///
/// ```
/// //- toolchain: nightly
/// //- proc_macros: identity
/// //- minicore: sized
/// ```
///
/// That will set toolchain to nightly and include predefined proc macros and a subset of
/// `libcore` into the fixture, see `minicore.rs` for what's available. Note that toolchain
/// defaults to stable.
pub fn parse(ra_fixture: &str) -> Self {
let fixture = trim_indent(ra_fixture);
let mut fixture = fixture.as_str();
let mut toolchain = None;
let mut target_data_layout =
"e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128".to_owned();
let mut mini_core = None;
let mut res: Vec<Fixture> = Vec::new();
let mut proc_macro_names = vec![];
if let Some(meta) = fixture.strip_prefix("//- toolchain:") {
let (meta, remain) = meta.split_once('\n').unwrap();
toolchain = Some(meta.trim().to_owned());
fixture = remain;
}
if let Some(meta) = fixture.strip_prefix("//- target_data_layout:") {
let (meta, remain) = meta.split_once('\n').unwrap();
target_data_layout = meta.trim().to_owned();
fixture = remain;
}
if let Some(meta) = fixture.strip_prefix("//- proc_macros:") {
let (meta, remain) = meta.split_once('\n').unwrap();
proc_macro_names = meta.split(',').map(|it| it.trim().to_owned()).collect();
fixture = remain;
}
if let Some(meta) = fixture.strip_prefix("//- minicore:") {
let (meta, remain) = meta.split_once('\n').unwrap();
mini_core = Some(MiniCore::parse(meta));
fixture = remain;
}
let default = if fixture.contains("//-") { None } else { Some("//- /main.rs") };
for (ix, line) in default.into_iter().chain(fixture.split_inclusive('\n')).enumerate() {
if line.contains("//-") {
assert!(
line.starts_with("//-"),
"Metadata line {ix} has invalid indentation. \
All metadata lines need to have the same indentation.\n\
The offending line: {line:?}"
);
}
if line.starts_with("//-") {
let meta = Self::parse_meta_line(line);
res.push(meta);
} else {
if line.starts_with("// ")
&& line.contains(':')
&& !line.contains("::")
&& !line.contains('.')
&& line.chars().all(|it| !it.is_uppercase())
{
panic!("looks like invalid metadata line: {line:?}");
}
if let Some(entry) = res.last_mut() {
entry.text.push_str(line);
}
}
}
Self { fixture: res, mini_core, proc_macro_names, toolchain, target_data_layout }
}
//- /lib.rs crate:foo deps:bar,baz cfg:foo=a,bar=b env:OUTDIR=path/to,OTHER=foo
fn parse_meta_line(meta: &str) -> Fixture {
assert!(meta.starts_with("//-"));
let meta = meta["//-".len()..].trim();
let mut components = meta.split_ascii_whitespace();
let path = components.next().expect("fixture meta must start with a path").to_owned();
assert!(path.starts_with('/'), "fixture path does not start with `/`: {path:?}");
let mut krate = None;
let mut deps = Vec::new();
let mut extern_prelude = None;
let mut edition = None;
let mut cfgs = Vec::new();
let mut env = FxHashMap::default();
let mut introduce_new_source_root = None;
let mut library = false;
for component in components {
if component == "library" {
library = true;
continue;
}
let (key, value) =
component.split_once(':').unwrap_or_else(|| panic!("invalid meta line: {meta:?}"));
match key {
"crate" => krate = Some(value.to_owned()),
"deps" => deps = value.split(',').map(|it| it.to_owned()).collect(),
"extern-prelude" => {
if value.is_empty() {
extern_prelude = Some(Vec::new());
} else {
extern_prelude =
Some(value.split(',').map(|it| it.to_owned()).collect::<Vec<_>>());
}
}
"edition" => edition = Some(value.to_owned()),
"cfg" => {
for entry in value.split(',') {
match entry.split_once('=') {
Some((k, v)) => cfgs.push((k.to_owned(), Some(v.to_owned()))),
None => cfgs.push((entry.to_owned(), None)),
}
}
}
"env" => {
for key in value.split(',') {
if let Some((k, v)) = key.split_once('=') {
env.insert(k.into(), v.into());
}
}
}
"new_source_root" => introduce_new_source_root = Some(value.to_owned()),
_ => panic!("bad component: {component:?}"),
}
}
for prelude_dep in extern_prelude.iter().flatten() {
assert!(
deps.contains(prelude_dep),
"extern-prelude {extern_prelude:?} must be a subset of deps {deps:?}"
);
}
Fixture {
path,
text: String::new(),
krate,
deps,
extern_prelude,
cfgs,
edition,
env,
introduce_new_source_root,
library,
}
}
}
impl MiniCore {
const RAW_SOURCE: &'static str = include_str!("./minicore.rs");
fn has_flag(&self, flag: &str) -> bool {
self.activated_flags.iter().any(|it| it == flag)
}
pub fn from_flags<'a>(flags: impl IntoIterator<Item = &'a str>) -> Self {
MiniCore {
activated_flags: flags.into_iter().map(|x| x.to_owned()).collect(),
valid_flags: Vec::new(),
}
}
#[track_caller]
fn assert_valid_flag(&self, flag: &str) {
if !self.valid_flags.iter().any(|it| it == flag) {
panic!("invalid flag: {flag:?}, valid flags: {:?}", self.valid_flags);
}
}
fn parse(line: &str) -> MiniCore {
let mut res = MiniCore { activated_flags: Vec::new(), valid_flags: Vec::new() };
for entry in line.trim().split(", ") {
if res.has_flag(entry) {
panic!("duplicate minicore flag: {entry:?}");
}
res.activated_flags.push(entry.to_owned());
}
res
}
pub fn available_flags() -> impl Iterator<Item = &'static str> {
let lines = MiniCore::RAW_SOURCE.split_inclusive('\n');
lines
.map_while(|x| x.strip_prefix("//!"))
.skip_while(|line| !line.contains("Available flags:"))
.skip(1)
.map(|x| x.split_once(':').unwrap().0.trim())
}
/// Strips parts of minicore.rs which are flagged by inactive flags.
///
/// This is probably over-engineered to support flags dependencies.
pub fn source_code(mut self) -> String {
let mut buf = String::new();
let mut lines = MiniCore::RAW_SOURCE.split_inclusive('\n');
let mut implications = Vec::new();
// Parse `//!` preamble and extract flags and dependencies.
let trim_doc: fn(&str) -> Option<&str> = |line| match line.strip_prefix("//!") {
Some(it) => Some(it),
None => {
assert!(line.trim().is_empty(), "expected empty line after minicore header");
None
}
};
for line in lines
.by_ref()
.map_while(trim_doc)
.skip_while(|line| !line.contains("Available flags:"))
.skip(1)
{
let (flag, deps) = line.split_once(':').unwrap();
let flag = flag.trim();
self.valid_flags.push(flag.to_owned());
implications.extend(
iter::repeat(flag)
.zip(deps.split(", ").map(str::trim).filter(|dep| !dep.is_empty())),
);
}
for (_, dep) in &implications {
self.assert_valid_flag(dep);
}
for flag in &self.activated_flags {
self.assert_valid_flag(flag);
}
// Fixed point loop to compute transitive closure of flags.
loop {
let mut changed = false;
for &(u, v) in &implications {
if self.has_flag(u) && !self.has_flag(v) {
self.activated_flags.push(v.to_owned());
changed = true;
}
}
if !changed {
break;
}
}
let mut active_regions = Vec::new();
let mut seen_regions = Vec::new();
for line in lines {
let trimmed = line.trim();
if let Some(region) = trimmed.strip_prefix("// region:") {
active_regions.push(region);
continue;
}
if let Some(region) = trimmed.strip_prefix("// endregion:") {
let prev = active_regions.pop().unwrap();
assert_eq!(prev, region, "unbalanced region pairs");
continue;
}
let mut line_region = false;
if let Some(idx) = trimmed.find("// :") {
line_region = true;
active_regions.push(&trimmed[idx + "// :".len()..]);
}
let mut keep = true;
for &region in &active_regions {
assert!(!region.starts_with(' '), "region marker starts with a space: {region:?}");
self.assert_valid_flag(region);
seen_regions.push(region);
keep &= self.has_flag(region);
}
if keep {
buf.push_str(line);
}
if line_region {
active_regions.pop().unwrap();
}
}
if !active_regions.is_empty() {
panic!("unclosed regions: {:?} Add an `endregion` comment", active_regions);
}
for flag in &self.valid_flags {
if !seen_regions.iter().any(|it| it == flag) {
panic!("unused minicore flag: {flag:?}");
}
}
buf
}
}
#[test]
#[should_panic]
fn parse_fixture_checks_further_indented_metadata() {
FixtureWithProjectMeta::parse(
r"
//- /lib.rs
mod bar;
fn foo() {}
//- /bar.rs
pub fn baz() {}
",
);
}
#[test]
fn parse_fixture_gets_full_meta() {
let FixtureWithProjectMeta {
fixture: parsed,
mini_core,
proc_macro_names,
toolchain,
target_data_layout: _,
} = FixtureWithProjectMeta::parse(
r#"
//- toolchain: nightly
//- proc_macros: identity
//- minicore: coerce_unsized
//- /lib.rs crate:foo deps:bar,baz cfg:foo=a,bar=b,atom env:OUTDIR=path/to,OTHER=foo
mod m;
"#,
);
assert_eq!(toolchain, Some("nightly".to_owned()));
assert_eq!(proc_macro_names, vec!["identity".to_owned()]);
assert_eq!(mini_core.unwrap().activated_flags, vec!["coerce_unsized".to_owned()]);
assert_eq!(1, parsed.len());
let meta = &parsed[0];
assert_eq!("mod m;\n", meta.text);
assert_eq!("foo", meta.krate.as_ref().unwrap());
assert_eq!("/lib.rs", meta.path);
assert_eq!(2, meta.env.len());
}