Simplify xtask

lib/bin/test separation isn't really needed.

16 files changed, 589 insertions, 176 deletions

diff --git a/xtask/src/codegen.rs b/xtask/src/codegen.rs
index adea053b6..743e83e76 100644
--- a/xtask/src/codegen.rs
+++ b/xtask/src/codegen.rs
@@ -20,7 +20,7 @@ use xshell::{cmd, pushenv, read_file, write_file};
 
 use crate::{ensure_rustfmt, project_root, Result};
 
-pub use self::{
+pub(crate) use self::{
     gen_assists_docs::{generate_assists_docs, generate_assists_tests},
     gen_diagnostic_docs::generate_diagnostic_docs,
     gen_feature_docs::generate_feature_docs,
@@ -30,17 +30,17 @@ pub use self::{
 };
 
 #[derive(Debug, PartialEq, Eq, Clone, Copy)]
-pub enum Mode {
+pub(crate) enum Mode {
     Overwrite,
     Verify,
 }
 
-pub struct CodegenCmd {
-    pub features: bool,
+pub(crate) struct CodegenCmd {
+    pub(crate) features: bool,
 }
 
 impl CodegenCmd {
-    pub fn run(self) -> Result<()> {
+    pub(crate) fn run(self) -> Result<()> {
         if self.features {
             generate_lint_completions(Mode::Overwrite)?;
         }
diff --git a/xtask/src/codegen/gen_assists_docs.rs b/xtask/src/codegen/gen_assists_docs.rs
index 1ae1343a5..c469b388d 100644
--- a/xtask/src/codegen/gen_assists_docs.rs
+++ b/xtask/src/codegen/gen_assists_docs.rs
@@ -7,12 +7,12 @@ use crate::{
     project_root, rust_files_in, Result,
 };
 
-pub fn generate_assists_tests(mode: Mode) -> Result<()> {
+pub(crate) fn generate_assists_tests(mode: Mode) -> Result<()> {
     let assists = Assist::collect()?;
     generate_tests(&assists, mode)
 }
 
-pub fn generate_assists_docs(mode: Mode) -> Result<()> {
+pub(crate) fn generate_assists_docs(mode: Mode) -> Result<()> {
     let assists = Assist::collect()?;
     let contents = assists.into_iter().map(|it| it.to_string()).collect::<Vec<_>>().join("\n\n");
     let contents = format!("//{}\n{}\n", PREAMBLE, contents.trim());
diff --git a/xtask/src/codegen/gen_diagnostic_docs.rs b/xtask/src/codegen/gen_diagnostic_docs.rs
index 7c14d4a07..a2561817b 100644
--- a/xtask/src/codegen/gen_diagnostic_docs.rs
+++ b/xtask/src/codegen/gen_diagnostic_docs.rs
@@ -7,7 +7,7 @@ use crate::{
     project_root, rust_files, Result,
 };
 
-pub fn generate_diagnostic_docs(mode: Mode) -> Result<()> {
+pub(crate) fn generate_diagnostic_docs(mode: Mode) -> Result<()> {
     let diagnostics = Diagnostic::collect()?;
     let contents =
         diagnostics.into_iter().map(|it| it.to_string()).collect::<Vec<_>>().join("\n\n");
diff --git a/xtask/src/codegen/gen_feature_docs.rs b/xtask/src/codegen/gen_feature_docs.rs
index 61081063b..cad7ff477 100644
--- a/xtask/src/codegen/gen_feature_docs.rs
+++ b/xtask/src/codegen/gen_feature_docs.rs
@@ -7,7 +7,7 @@ use crate::{
     project_root, rust_files, Result,
 };
 
-pub fn generate_feature_docs(mode: Mode) -> Result<()> {
+pub(crate) fn generate_feature_docs(mode: Mode) -> Result<()> {
     let features = Feature::collect()?;
     let contents = features.into_iter().map(|it| it.to_string()).collect::<Vec<_>>().join("\n\n");
     let contents = format!("//{}\n{}\n", PREAMBLE, contents.trim());
diff --git a/xtask/src/codegen/gen_lint_completions.rs b/xtask/src/codegen/gen_lint_completions.rs
index 8c51d35c7..b1c057037 100644
--- a/xtask/src/codegen/gen_lint_completions.rs
+++ b/xtask/src/codegen/gen_lint_completions.rs
@@ -10,7 +10,7 @@ use crate::{
     run_rustfmt,
 };
 
-pub fn generate_lint_completions(mode: Mode) -> Result<()> {
+pub(crate) fn generate_lint_completions(mode: Mode) -> Result<()> {
     if !Path::new("./target/rust").exists() {
         cmd!("git clone --depth=1 https://github.com/rust-lang/rust ./target/rust").run()?;
     }
diff --git a/xtask/src/codegen/gen_parser_tests.rs b/xtask/src/codegen/gen_parser_tests.rs
index 6e4abd10c..cb8939063 100644
--- a/xtask/src/codegen/gen_parser_tests.rs
+++ b/xtask/src/codegen/gen_parser_tests.rs
@@ -12,7 +12,7 @@ use crate::{
     project_root, Result,
 };
 
-pub fn generate_parser_tests(mode: Mode) -> Result<()> {
+pub(crate) fn generate_parser_tests(mode: Mode) -> Result<()> {
     let tests = tests_from_dir(&project_root().join(Path::new("crates/parser/src/grammar")))?;
     fn install_tests(tests: &HashMap<String, Test>, into: &str, mode: Mode) -> Result<()> {
         let tests_dir = project_root().join(into);
diff --git a/xtask/src/codegen/gen_syntax.rs b/xtask/src/codegen/gen_syntax.rs
index eb524d85a..191bc0e9d 100644
--- a/xtask/src/codegen/gen_syntax.rs
+++ b/xtask/src/codegen/gen_syntax.rs
@@ -18,7 +18,7 @@ use crate::{
     project_root, Result,
 };
 
-pub fn generate_syntax(mode: Mode) -> Result<()> {
+pub(crate) fn generate_syntax(mode: Mode) -> Result<()> {
     let grammar = rust_grammar();
     let ast = lower(&grammar);
 
diff --git a/xtask/src/dist.rs b/xtask/src/dist.rs
index 56bf9f99d..f2503f807 100644
--- a/xtask/src/dist.rs
+++ b/xtask/src/dist.rs
@@ -11,13 +11,13 @@ use xshell::{cmd, cp, mkdir_p, pushd, read_file, rm_rf, write_file};
 
 use crate::{date_iso, project_root};
 
-pub struct DistCmd {
-    pub nightly: bool,
-    pub client_version: Option<String>,
+pub(crate) struct DistCmd {
+    pub(crate) nightly: bool,
+    pub(crate) client_version: Option<String>,
 }
 
 impl DistCmd {
-    pub fn run(self) -> Result<()> {
+    pub(crate) fn run(self) -> Result<()> {
         let dist = project_root().join("dist");
         rm_rf(&dist)?;
         mkdir_p(&dist)?;
diff --git a/xtask/src/install.rs b/xtask/src/install.rs
index 4c5c2673c..ea2194248 100644
--- a/xtask/src/install.rs
+++ b/xtask/src/install.rs
@@ -8,13 +8,13 @@ use xshell::{cmd, pushd};
 // Latest stable, feel free to send a PR if this lags behind.
 const REQUIRED_RUST_VERSION: u32 = 50;
 
-pub struct InstallCmd {
-    pub client: Option<ClientOpt>,
-    pub server: Option<ServerOpt>,
+pub(crate) struct InstallCmd {
+    pub(crate) client: Option<ClientOpt>,
+    pub(crate) server: Option<ServerOpt>,
 }
 
 #[derive(Clone, Copy)]
-pub enum ClientOpt {
+pub(crate) enum ClientOpt {
     VsCode,
     VsCodeExploration,
     VsCodeInsiders,
@@ -24,7 +24,7 @@ pub enum ClientOpt {
 }
 
 impl ClientOpt {
-    pub const fn as_cmds(&self) -> &'static [&'static str] {
+    pub(crate) const fn as_cmds(&self) -> &'static [&'static str] {
         match self {
             ClientOpt::VsCode => &["code"],
             ClientOpt::VsCodeExploration => &["code-exploration"],
@@ -60,18 +60,18 @@ impl std::str::FromStr for ClientOpt {
     }
 }
 
-pub struct ServerOpt {
-    pub malloc: Malloc,
+pub(crate) struct ServerOpt {
+    pub(crate) malloc: Malloc,
 }
 
-pub enum Malloc {
+pub(crate) enum Malloc {
     System,
     Mimalloc,
     Jemalloc,
 }
 
 impl InstallCmd {
-    pub fn run(self) -> Result<()> {
+    pub(crate) fn run(self) -> Result<()> {
         if cfg!(target_os = "macos") {
             fix_path_for_mac().context("Fix path for mac")?
         }
diff --git a/xtask/src/lib.rs b/xtask/src/lib.rs
deleted file mode 100644
index b19985fb2..000000000
--- a/xtask/src/lib.rs
+++ /dev/null
@@ -1,131 +0,0 @@
-//! Support library for `cargo xtask` command.
-//!
-//! See https://github.com/matklad/cargo-xtask/
-
-pub mod codegen;
-mod ast_src;
-
-pub mod install;
-pub mod release;
-pub mod dist;
-pub mod pre_commit;
-pub mod metrics;
-pub mod pre_cache;
-
-use std::{
-    env,
-    path::{Path, PathBuf},
-};
-
-use walkdir::{DirEntry, WalkDir};
-use xshell::{cmd, pushd, pushenv};
-
-use crate::codegen::Mode;
-
-pub use anyhow::{bail, Context as _, Result};
-
-pub fn project_root() -> PathBuf {
-    Path::new(
-        &env::var("CARGO_MANIFEST_DIR").unwrap_or_else(|_| env!("CARGO_MANIFEST_DIR").to_owned()),
-    )
-    .ancestors()
-    .nth(1)
-    .unwrap()
-    .to_path_buf()
-}
-
-pub fn rust_files() -> impl Iterator<Item = PathBuf> {
-    rust_files_in(&project_root().join("crates"))
-}
-
-pub fn cargo_files() -> impl Iterator<Item = PathBuf> {
-    files_in(&project_root(), "toml")
-        .filter(|path| path.file_name().map(|it| it == "Cargo.toml").unwrap_or(false))
-}
-
-pub fn rust_files_in(path: &Path) -> impl Iterator<Item = PathBuf> {
-    files_in(path, "rs")
-}
-
-pub fn run_rustfmt(mode: Mode) -> Result<()> {
-    let _dir = pushd(project_root())?;
-    let _e = pushenv("RUSTUP_TOOLCHAIN", "stable");
-    ensure_rustfmt()?;
-    let check = match mode {
-        Mode::Overwrite => &[][..],
-        Mode::Verify => &["--", "--check"],
-    };
-    cmd!("cargo fmt {check...}").run()?;
-    Ok(())
-}
-
-fn ensure_rustfmt() -> Result<()> {
-    let out = cmd!("rustfmt --version").read()?;
-    if !out.contains("stable") {
-        bail!(
-            "Failed to run rustfmt from toolchain 'stable'. \
-             Please run `rustup component add rustfmt --toolchain stable` to install it.",
-        )
-    }
-    Ok(())
-}
-
-pub fn run_clippy() -> Result<()> {
-    if cmd!("cargo clippy --version").read().is_err() {
-        bail!(
-            "Failed run cargo clippy. \
-            Please run `rustup component add clippy` to install it.",
-        )
-    }
-
-    let allowed_lints = "
-        -A clippy::collapsible_if
-        -A clippy::needless_pass_by_value
-        -A clippy::nonminimal_bool
-        -A clippy::redundant_pattern_matching
-    "
-    .split_ascii_whitespace();
-    cmd!("cargo clippy --all-features --all-targets -- {allowed_lints...}").run()?;
-    Ok(())
-}
-
-pub fn run_fuzzer() -> Result<()> {
-    let _d = pushd("./crates/syntax")?;
-    let _e = pushenv("RUSTUP_TOOLCHAIN", "nightly");
-    if cmd!("cargo fuzz --help").read().is_err() {
-        cmd!("cargo install cargo-fuzz").run()?;
-    };
-
-    // Expecting nightly rustc
-    let out = cmd!("rustc --version").read()?;
-    if !out.contains("nightly") {
-        bail!("fuzz tests require nightly rustc")
-    }
-
-    cmd!("cargo fuzz run parser").run()?;
-    Ok(())
-}
-
-fn date_iso() -> Result<String> {
-    let res = cmd!("date --iso --utc").read()?;
-    Ok(res)
-}
-
-fn is_release_tag(tag: &str) -> bool {
-    tag.len() == "2020-02-24".len() && tag.starts_with(|c: char| c.is_ascii_digit())
-}
-
-fn files_in(path: &Path, ext: &'static str) -> impl Iterator<Item = PathBuf> {
-    let iter = WalkDir::new(path);
-    return iter
-        .into_iter()
-        .filter_entry(|e| !is_hidden(e))
-        .map(|e| e.unwrap())
-        .filter(|e| !e.file_type().is_dir())
-        .map(|e| e.into_path())
-        .filter(move |path| path.extension().map(|it| it == ext).unwrap_or(false));
-
-    fn is_hidden(entry: &DirEntry) -> bool {
-        entry.file_name().to_str().map(|s| s.starts_with('.')).unwrap_or(false)
-    }
-}
diff --git a/xtask/src/main.rs b/xtask/src/main.rs
index cbb9b315e..48c0d9920 100644
--- a/xtask/src/main.rs
+++ b/xtask/src/main.rs
@@ -7,22 +7,35 @@
 //!
 //! This binary is integrated into the `cargo` command line by using an alias in
 //! `.cargo/config`.
+mod codegen;
+mod ast_src;
+#[cfg(test)]
+mod tidy;
 
-use std::env;
+mod install;
+mod release;
+mod dist;
+mod pre_commit;
+mod metrics;
+mod pre_cache;
 
-use anyhow::bail;
+use anyhow::{bail, Result};
 use codegen::CodegenCmd;
 use pico_args::Arguments;
-use xshell::{cmd, cp, pushd};
-use xtask::{
-    codegen::{self, Mode},
+use std::{
+    env,
+    path::{Path, PathBuf},
+};
+use walkdir::{DirEntry, WalkDir};
+use xshell::{cmd, cp, pushd, pushenv};
+
+use crate::{
+    codegen::Mode,
     dist::DistCmd,
     install::{InstallCmd, Malloc, ServerOpt},
     metrics::MetricsCmd,
     pre_cache::PreCacheCmd,
-    pre_commit, project_root,
     release::{PromoteCmd, ReleaseCmd},
-    run_clippy, run_fuzzer, run_rustfmt, Result,
 };
 
 fn main() -> Result<()> {
@@ -172,3 +185,110 @@ fn finish_args(args: Arguments) -> Result<()> {
     }
     Ok(())
 }
+
+fn project_root() -> PathBuf {
+    Path::new(
+        &env::var("CARGO_MANIFEST_DIR").unwrap_or_else(|_| env!("CARGO_MANIFEST_DIR").to_owned()),
+    )
+    .ancestors()
+    .nth(1)
+    .unwrap()
+    .to_path_buf()
+}
+
+fn rust_files() -> impl Iterator<Item = PathBuf> {
+    rust_files_in(&project_root().join("crates"))
+}
+
+#[cfg(test)]
+fn cargo_files() -> impl Iterator<Item = PathBuf> {
+    files_in(&project_root(), "toml")
+        .filter(|path| path.file_name().map(|it| it == "Cargo.toml").unwrap_or(false))
+}
+
+fn rust_files_in(path: &Path) -> impl Iterator<Item = PathBuf> {
+    files_in(path, "rs")
+}
+
+fn run_rustfmt(mode: Mode) -> Result<()> {
+    let _dir = pushd(project_root())?;
+    let _e = pushenv("RUSTUP_TOOLCHAIN", "stable");
+    ensure_rustfmt()?;
+    let check = match mode {
+        Mode::Overwrite => &[][..],
+        Mode::Verify => &["--", "--check"],
+    };
+    cmd!("cargo fmt {check...}").run()?;
+    Ok(())
+}
+
+fn ensure_rustfmt() -> Result<()> {
+    let out = cmd!("rustfmt --version").read()?;
+    if !out.contains("stable") {
+        bail!(
+            "Failed to run rustfmt from toolchain 'stable'. \
+             Please run `rustup component add rustfmt --toolchain stable` to install it.",
+        )
+    }
+    Ok(())
+}
+
+fn run_clippy() -> Result<()> {
+    if cmd!("cargo clippy --version").read().is_err() {
+        bail!(
+            "Failed run cargo clippy. \
+            Please run `rustup component add clippy` to install it.",
+        )
+    }
+
+    let allowed_lints = "
+        -A clippy::collapsible_if
+        -A clippy::needless_pass_by_value
+        -A clippy::nonminimal_bool
+        -A clippy::redundant_pattern_matching
+    "
+    .split_ascii_whitespace();
+    cmd!("cargo clippy --all-features --all-targets -- {allowed_lints...}").run()?;
+    Ok(())
+}
+
+fn run_fuzzer() -> Result<()> {
+    let _d = pushd("./crates/syntax")?;
+    let _e = pushenv("RUSTUP_TOOLCHAIN", "nightly");
+    if cmd!("cargo fuzz --help").read().is_err() {
+        cmd!("cargo install cargo-fuzz").run()?;
+    };
+
+    // Expecting nightly rustc
+    let out = cmd!("rustc --version").read()?;
+    if !out.contains("nightly") {
+        bail!("fuzz tests require nightly rustc")
+    }
+
+    cmd!("cargo fuzz run parser").run()?;
+    Ok(())
+}
+
+fn date_iso() -> Result<String> {
+    let res = cmd!("date --iso --utc").read()?;
+    Ok(res)
+}
+
+fn is_release_tag(tag: &str) -> bool {
+    tag.len() == "2020-02-24".len() && tag.starts_with(|c: char| c.is_ascii_digit())
+}
+
+fn files_in(path: &Path, ext: &'static str) -> impl Iterator<Item = PathBuf> {
+    let iter = WalkDir::new(path);
+    return iter
+        .into_iter()
+        .filter_entry(|e| !is_hidden(e))
+        .map(|e| e.unwrap())
+        .filter(|e| !e.file_type().is_dir())
+        .map(|e| e.into_path())
+        .filter(move |path| path.extension().map(|it| it == ext).unwrap_or(false));
+
+    fn is_hidden(entry: &DirEntry) -> bool {
+        entry.file_name().to_str().map(|s| s.starts_with('.')).unwrap_or(false)
+    }
+}
diff --git a/xtask/src/metrics.rs b/xtask/src/metrics.rs
index 624ad3b7e..babc2a6d4 100644
--- a/xtask/src/metrics.rs
+++ b/xtask/src/metrics.rs
@@ -11,12 +11,12 @@ use xshell::{cmd, mkdir_p, pushd, pushenv, read_file, rm_rf};
 
 type Unit = String;
 
-pub struct MetricsCmd {
-    pub dry_run: bool,
+pub(crate) struct MetricsCmd {
+    pub(crate) dry_run: bool,
 }
 
 impl MetricsCmd {
-    pub fn run(self) -> Result<()> {
+    pub(crate) fn run(self) -> Result<()> {
         let mut metrics = Metrics::new()?;
         if !self.dry_run {
             rm_rf("./target/release")?;
diff --git a/xtask/src/pre_cache.rs b/xtask/src/pre_cache.rs
index 569f88f68..54f4a95a9 100644
--- a/xtask/src/pre_cache.rs
+++ b/xtask/src/pre_cache.rs
@@ -6,12 +6,12 @@ use std::{
 use anyhow::Result;
 use xshell::rm_rf;
 
-pub struct PreCacheCmd;
+pub(crate) struct PreCacheCmd;
 
 impl PreCacheCmd {
     /// Cleans the `./target` dir after the build such that only
     /// dependencies are cached on CI.
-    pub fn run(self) -> Result<()> {
+    pub(crate) fn run(self) -> Result<()> {
         let slow_tests_cookie = Path::new("./target/.slow_tests_cookie");
         if !slow_tests_cookie.exists() {
             panic!("slow tests were skipped on CI!")
diff --git a/xtask/src/pre_commit.rs b/xtask/src/pre_commit.rs
index 8f2dbea19..b57cf3ce2 100644
--- a/xtask/src/pre_commit.rs
+++ b/xtask/src/pre_commit.rs
@@ -9,7 +9,7 @@ use crate::{project_root, run_rustfmt, Mode};
 
 // FIXME: if there are changed `.ts` files, also reformat TypeScript (by
 // shelling out to `npm fmt`).
-pub fn run_hook() -> Result<()> {
+pub(crate) fn run_hook() -> Result<()> {
     run_rustfmt(Mode::Overwrite)?;
 
     let diff = cmd!("git diff --diff-filter=MAR --name-only --cached").read()?;
@@ -23,7 +23,7 @@ pub fn run_hook() -> Result<()> {
     Ok(())
 }
 
-pub fn install_hook() -> Result<()> {
+pub(crate) fn install_hook() -> Result<()> {
     let hook_path: PathBuf =
         format!("./.git/hooks/pre-commit{}", std::env::consts::EXE_SUFFIX).into();
 
diff --git a/xtask/src/release.rs b/xtask/src/release.rs
index 63556476d..5008881e4 100644
--- a/xtask/src/release.rs
+++ b/xtask/src/release.rs
@@ -4,12 +4,12 @@ use xshell::{cmd, cp, pushd, read_dir, write_file};
 
 use crate::{codegen, date_iso, is_release_tag, project_root, Mode, Result};
 
-pub struct ReleaseCmd {
-    pub dry_run: bool,
+pub(crate) struct ReleaseCmd {
+    pub(crate) dry_run: bool,
 }
 
 impl ReleaseCmd {
-    pub fn run(self) -> Result<()> {
+    pub(crate) fn run(self) -> Result<()> {
         if !self.dry_run {
             cmd!("git switch release").run()?;
             cmd!("git fetch upstream --tags --force").run()?;
@@ -86,12 +86,12 @@ https://github.com/sponsors/rust-analyzer[GitHub Sponsors].
     }
 }
 
-pub struct PromoteCmd {
-    pub dry_run: bool,
+pub(crate) struct PromoteCmd {
+    pub(crate) dry_run: bool,
 }
 
 impl PromoteCmd {
-    pub fn run(self) -> Result<()> {
+    pub(crate) fn run(self) -> Result<()> {
         let _dir = pushd("../rust-rust-analyzer")?;
         cmd!("git switch master").run()?;
         cmd!("git fetch upstream").run()?;
diff --git a/xtask/src/tidy.rs b/xtask/src/tidy.rs
new file mode 100644
index 000000000..63116ec6b
--- /dev/null
+++ b/xtask/src/tidy.rs
@@ -0,0 +1,424 @@
+use std::{
+    collections::HashMap,
+    path::{Path, PathBuf},
+};
+
+use xshell::{cmd, read_file};
+
+use crate::{
+    cargo_files,
+    codegen::{self, Mode},
+    project_root, run_rustfmt, rust_files,
+};
+
+#[test]
+fn generated_grammar_is_fresh() {
+    if let Err(error) = codegen::generate_syntax(Mode::Verify) {
+        panic!("{}. Please update it by running `cargo xtask codegen`", error);
+    }
+}
+
+#[test]
+fn generated_tests_are_fresh() {
+    if let Err(error) = codegen::generate_parser_tests(Mode::Verify) {
+        panic!("{}. Please update tests by running `cargo xtask codegen`", error);
+    }
+}
+
+#[test]
+fn generated_assists_are_fresh() {
+    if let Err(error) = codegen::generate_assists_tests(Mode::Verify) {
+        panic!("{}. Please update assists by running `cargo xtask codegen`", error);
+    }
+}
+
+#[test]
+fn check_code_formatting() {
+    if let Err(error) = run_rustfmt(Mode::Verify) {
+        panic!("{}. Please format the code by running `cargo format`", error);
+    }
+}
+
+#[test]
+fn smoke_test_docs_generation() {
+    // We don't commit docs to the repo, so we can just overwrite in tests.
+    codegen::generate_assists_docs(Mode::Overwrite).unwrap();
+    codegen::generate_feature_docs(Mode::Overwrite).unwrap();
+    codegen::generate_diagnostic_docs(Mode::Overwrite).unwrap();
+}
+
+#[test]
+fn check_lsp_extensions_docs() {
+    let expected_hash = {
+        let lsp_ext_rs =
+            read_file(project_root().join("crates/rust-analyzer/src/lsp_ext.rs")).unwrap();
+        stable_hash(lsp_ext_rs.as_str())
+    };
+
+    let actual_hash = {
+        let lsp_extensions_md =
+            read_file(project_root().join("docs/dev/lsp-extensions.md")).unwrap();
+        let text = lsp_extensions_md
+            .lines()
+            .find_map(|line| line.strip_prefix("lsp_ext.rs hash:"))
+            .unwrap()
+            .trim();
+        u64::from_str_radix(text, 16).unwrap()
+    };
+
+    if actual_hash != expected_hash {
+        panic!(
+            "
+lsp_ext.rs was changed without touching lsp-extensions.md.
+
+Expected hash: {:x}
+Actual hash:   {:x}
+
+Please adjust docs/dev/lsp-extensions.md.
+",
+            expected_hash, actual_hash
+        )
+    }
+}
+
+#[test]
+fn rust_files_are_tidy() {
+    let mut tidy_docs = TidyDocs::default();
+    for path in rust_files() {
+        let text = read_file(&path).unwrap();
+        check_todo(&path, &text);
+        check_dbg(&path, &text);
+        check_trailing_ws(&path, &text);
+        deny_clippy(&path, &text);
+        tidy_docs.visit(&path, &text);
+    }
+    tidy_docs.finish();
+}
+
+#[test]
+fn cargo_files_are_tidy() {
+    for cargo in cargo_files() {
+        let mut section = None;
+        for (line_no, text) in read_file(&cargo).unwrap().lines().enumerate() {
+            let text = text.trim();
+            if text.starts_with("[") {
+                section = Some(text);
+                continue;
+            }
+            if !section.map(|it| it.starts_with("[dependencies")).unwrap_or(false) {
+                continue;
+            }
+            let text: String = text.split_whitespace().collect();
+            if text.contains("path=") && !text.contains("version") {
+                panic!(
+                    "\ncargo internal dependencies should have version.\n\
+                     {}:{}\n",
+                    cargo.display(),
+                    line_no + 1
+                )
+            }
+        }
+    }
+}
+
+#[test]
+fn check_merge_commits() {
+    let stdout = cmd!("git rev-list --merges --invert-grep --author 'bors\\[bot\\]' HEAD~19..")
+        .read()
+        .unwrap();
+    if !stdout.is_empty() {
+        panic!(
+            "
+Merge commits are not allowed in the history.
+
+When updating a pull-request, please rebase your feature branch
+on top of master by running `git rebase master`. If rebase fails,
+you can re-apply your changes like this:
+
+  # Just look around to see the current state.
+  $ git status
+  $ git log
+
+  # Abort in-progress rebase and merges, if any.
+  $ git rebase --abort
+  $ git merge --abort
+
+  # Make the branch point to the latest commit from master,
+  # while maintaining your local changes uncommited.
+  $ git reset --soft origin/master
+
+  # Commit all changes in a single batch.
+  $ git commit -am'My changes'
+
+  # Verify that everything looks alright.
+  $ git status
+  $ git log
+
+  # Push the changes. We did a rebase, so we need `--force` option.
+  # `--force-with-lease` is a more safe (Rusty) version of `--force`.
+  $ git push --force-with-lease
+
+  # Verify that both local and remote branch point to the same commit.
+  $ git log
+
+And don't fear to mess something up during a rebase -- you can
+always restore the previous state using `git ref-log`:
+
+https://github.blog/2015-06-08-how-to-undo-almost-anything-with-git/#redo-after-undo-local
+"
+        );
+    }
+}
+
+fn deny_clippy(path: &PathBuf, text: &String) {
+    let ignore = &[
+        // The documentation in string literals may contain anything for its own purposes
+        "ide_completion/src/generated_lint_completions.rs",
+    ];
+    if ignore.iter().any(|p| path.ends_with(p)) {
+        return;
+    }
+
+    if text.contains("\u{61}llow(clippy") {
+        panic!(
+            "\n\nallowing lints is forbidden: {}.
+rust-analyzer intentionally doesn't check clippy on CI.
+You can allow lint globally via `xtask clippy`.
+See https://github.com/rust-lang/rust-clippy/issues/5537 for discussion.
+
+",
+            path.display()
+        )
+    }
+}
+
+#[test]
+fn check_licenses() {
+    let expected = "
+0BSD OR MIT OR Apache-2.0
+Apache-2.0
+Apache-2.0 OR BSL-1.0
+Apache-2.0 OR MIT
+Apache-2.0/MIT
+BSD-3-Clause
+CC0-1.0
+ISC
+MIT
+MIT / Apache-2.0
+MIT OR Apache-2.0
+MIT OR Apache-2.0 OR Zlib
+MIT OR Zlib OR Apache-2.0
+MIT/Apache-2.0
+Unlicense OR MIT
+Unlicense/MIT
+Zlib OR Apache-2.0 OR MIT
+"
+    .lines()
+    .filter(|it| !it.is_empty())
+    .collect::<Vec<_>>();
+
+    let meta = cmd!("cargo metadata --format-version 1").read().unwrap();
+    let mut licenses = meta
+        .split(|c| c == ',' || c == '{' || c == '}')
+        .filter(|it| it.contains(r#""license""#))
+        .map(|it| it.trim())
+        .map(|it| it[r#""license":"#.len()..].trim_matches('"'))
+        .collect::<Vec<_>>();
+    licenses.sort();
+    licenses.dedup();
+    if licenses != expected {
+        let mut diff = String::new();
+
+        diff += &format!("New Licenses:\n");
+        for &l in licenses.iter() {
+            if !expected.contains(&l) {
+                diff += &format!("  {}\n", l)
+            }
+        }
+
+        diff += &format!("\nMissing Licenses:\n");
+        for &l in expected.iter() {
+            if !licenses.contains(&l) {
+                diff += &format!("  {}\n", l)
+            }
+        }
+
+        panic!("different set of licenses!\n{}", diff);
+    }
+    assert_eq!(licenses, expected);
+}
+
+fn check_todo(path: &Path, text: &str) {
+    let need_todo = &[
+        // This file itself obviously needs to use todo (<- like this!).
+        "tests/tidy.rs",
+        // Some of our assists generate `todo!()`.
+        "handlers/add_turbo_fish.rs",
+        "handlers/generate_function.rs",
+        // To support generating `todo!()` in assists, we have `expr_todo()` in
+        // `ast::make`.
+        "ast/make.rs",
+        // The documentation in string literals may contain anything for its own purposes
+        "ide_completion/src/generated_lint_completions.rs",
+    ];
+    if need_todo.iter().any(|p| path.ends_with(p)) {
+        return;
+    }
+    if text.contains("TODO") || text.contains("TOOD") || text.contains("todo!") {
+        // Generated by an assist
+        if text.contains("${0:todo!()}") {
+            return;
+        }
+
+        panic!(
+            "\nTODO markers or todo! macros should not be committed to the master branch,\n\
+             use FIXME instead\n\
+             {}\n",
+            path.display(),
+        )
+    }
+}
+
+fn check_dbg(path: &Path, text: &str) {
+    let need_dbg = &[
+        // This file itself obviously needs to use dbg.
+        "tests/tidy.rs",
+        // Assists to remove `dbg!()`
+        "handlers/remove_dbg.rs",
+        // We have .dbg postfix
+        "ide_completion/src/completions/postfix.rs",
+        // The documentation in string literals may contain anything for its own purposes
+        "ide_completion/src/lib.rs",
+        "ide_completion/src/generated_lint_completions.rs",
+        // test for doc test for remove_dbg
+        "src/tests/generated.rs",
+    ];
+    if need_dbg.iter().any(|p| path.ends_with(p)) {
+        return;
+    }
+    if text.contains("dbg!") {
+        panic!(
+            "\ndbg! macros should not be committed to the master branch,\n\
+             {}\n",
+            path.display(),
+        )
+    }
+}
+
+fn check_trailing_ws(path: &Path, text: &str) {
+    if is_exclude_dir(path, &["test_data"]) {
+        return;
+    }
+    for (line_number, line) in text.lines().enumerate() {
+        if line.chars().last().map(char::is_whitespace) == Some(true) {
+            panic!("Trailing whitespace in {} at line {}", path.display(), line_number)
+        }
+    }
+}
+
+#[derive(Default)]
+struct TidyDocs {
+    missing_docs: Vec<String>,
+    contains_fixme: Vec<PathBuf>,
+}
+
+impl TidyDocs {
+    fn visit(&mut self, path: &Path, text: &str) {
+        // Test hopefully don't really need comments, and for assists we already
+        // have special comments which are source of doc tests and user docs.
+        if is_exclude_dir(path, &["tests", "test_data"]) {
+            return;
+        }
+
+        if is_exclude_file(path) {
+            return;
+        }
+
+        let first_line = match text.lines().next() {
+            Some(it) => it,
+            None => return,
+        };
+
+        if first_line.starts_with("//!") {
+            if first_line.contains("FIXME") {
+                self.contains_fixme.push(path.to_path_buf());
+            }
+        } else {
+            if text.contains("// Feature:") || text.contains("// Assist:") {
+                return;
+            }
+            self.missing_docs.push(path.display().to_string());
+        }
+
+        fn is_exclude_file(d: &Path) -> bool {
+            let file_names = ["tests.rs", "famous_defs_fixture.rs"];
+
+            d.file_name()
+                .unwrap_or_default()
+                .to_str()
+                .map(|f_n| file_names.iter().any(|name| *name == f_n))
+                .unwrap_or(false)
+        }
+    }
+
+    fn finish(self) {
+        if !self.missing_docs.is_empty() {
+            panic!(
+                "\nMissing docs strings\n\n\
+                 modules:\n{}\n\n",
+                self.missing_docs.join("\n")
+            )
+        }
+
+        let poorly_documented = [
+            "hir",
+            "hir_expand",
+            "ide",
+            "mbe",
+            "parser",
+            "profile",
+            "project_model",
+            "syntax",
+            "tt",
+            "hir_ty",
+        ];
+
+        let mut has_fixmes =
+            poorly_documented.iter().map(|it| (*it, false)).collect::<HashMap<&str, bool>>();
+        'outer: for path in self.contains_fixme {
+            for krate in poorly_documented.iter() {
+                if path.components().any(|it| it.as_os_str() == *krate) {
+                    has_fixmes.insert(krate, true);
+                    continue 'outer;
+                }
+            }
+            panic!("FIXME doc in a fully-documented crate: {}", path.display())
+        }
+
+        for (krate, has_fixme) in has_fixmes.iter() {
+            if !has_fixme {
+                panic!("crate {} is fully documented :tada:, remove it from the list of poorly documented crates", krate)
+            }
+        }
+    }
+}
+
+fn is_exclude_dir(p: &Path, dirs_to_exclude: &[&str]) -> bool {
+    p.strip_prefix(project_root())
+        .unwrap()
+        .components()
+        .rev()
+        .skip(1)
+        .filter_map(|it| it.as_os_str().to_str())
+        .any(|it| dirs_to_exclude.contains(&it))
+}
+
+#[allow(deprecated)]
+fn stable_hash(text: &str) -> u64 {
+    use std::hash::{Hash, Hasher, SipHasher};
+
+    let text = text.replace('\r', "");
+    let mut hasher = SipHasher::default();
+    text.hash(&mut hasher);
+    hasher.finish()
+}