13 files changed, 313 insertions, 240 deletions

diff --git a/crates/ra_hir/src/docs.rs b/crates/ra_hir/src/docs.rs
index b1b47af9e..5db72c08a 100644
--- a/crates/ra_hir/src/docs.rs
+++ b/crates/ra_hir/src/docs.rs
@@ -27,10 +27,5 @@ pub trait Docs {
 }
 
 pub(crate) fn docs_from_ast(node: &impl ast::DocCommentsOwner) -> Option<Documentation> {
-    let comments = node.doc_comment_text();
-    if comments.is_empty() {
-        None
-    } else {
-        Some(Documentation::new(&comments))
-    }
+    node.doc_comment_text().map(|it| Documentation::new(&it))
 }
diff --git a/crates/ra_ide_api/src/call_info.rs b/crates/ra_ide_api/src/call_info.rs
index f203a6bf1..ee1e13799 100644
--- a/crates/ra_ide_api/src/call_info.rs
+++ b/crates/ra_ide_api/src/call_info.rs
@@ -126,8 +126,7 @@ impl CallInfo {
         };
 
         let mut doc = None;
-        let docs = node.doc_comment_text();
-        if !docs.is_empty() {
+        if let Some(docs) = node.doc_comment_text() {
             // Massage markdown
             let mut processed_lines = Vec::new();
             let mut in_code_block = false;
diff --git a/crates/ra_ide_api/src/hover.rs b/crates/ra_ide_api/src/hover.rs
index ff9ae2d9c..f993a461c 100644
--- a/crates/ra_ide_api/src/hover.rs
+++ b/crates/ra_ide_api/src/hover.rs
@@ -100,12 +100,7 @@ impl NavigationTarget {
     fn docs(&self, db: &RootDatabase) -> Option<String> {
         let node = self.node(db)?;
         fn doc_comments<N: ast::DocCommentsOwner>(node: &N) -> Option<String> {
-            let comments = node.doc_comment_text();
-            if comments.is_empty() {
-                None
-            } else {
-                Some(comments)
-            }
+            node.doc_comment_text()
         }
 
         visitor()
diff --git a/crates/ra_syntax/src/ast.rs b/crates/ra_syntax/src/ast.rs
index ab3dd1b84..3d22a88f3 100644
--- a/crates/ra_syntax/src/ast.rs
+++ b/crates/ra_syntax/src/ast.rs
@@ -115,21 +115,38 @@ pub trait DocCommentsOwner: AstNode {
     }
 
     /// Returns the textual content of a doc comment block as a single string.
-    /// That is, strips leading `///` and joins lines
-    fn doc_comment_text(&self) -> std::string::String {
-        self.doc_comments()
+    /// That is, strips leading `///` (+ optional 1 character of whitespace)
+    /// and joins lines.
+    fn doc_comment_text(&self) -> Option<std::string::String> {
+        let docs = self
+            .doc_comments()
             .filter(|comment| comment.is_doc_comment())
             .map(|comment| {
-                let prefix = comment.prefix();
-                let trimmed = comment
-                    .text()
-                    .as_str()
-                    .trim()
-                    .trim_start_matches(prefix)
-                    .trim_start();
-                trimmed.to_owned()
+                let prefix_len = comment.prefix().len();
+
+                let line = comment.text().as_str();
+
+                // Determine if the prefix or prefix + 1 char is stripped
+                let pos = if line
+                    .chars()
+                    .nth(prefix_len)
+                    .map(|c| c.is_whitespace())
+                    .unwrap_or(false)
+                {
+                    prefix_len + 1
+                } else {
+                    prefix_len
+                };
+
+                line[pos..].to_owned()
             })
-            .join("\n")
+            .join("\n");
+
+        if docs.is_empty() {
+            None
+        } else {
+            Some(docs)
+        }
     }
 }
 
@@ -704,6 +721,18 @@ impl BindPat {
 }
 
 #[test]
+fn test_doc_comment_none() {
+    let file = SourceFile::parse(
+        r#"
+        // non-doc
+        mod foo {}
+        "#,
+    );
+    let module = file.syntax().descendants().find_map(Module::cast).unwrap();
+    assert!(module.doc_comment_text().is_none());
+}
+
+#[test]
 fn test_doc_comment_of_items() {
     let file = SourceFile::parse(
         r#"
@@ -713,5 +742,25 @@ fn test_doc_comment_of_items() {
         "#,
     );
     let module = file.syntax().descendants().find_map(Module::cast).unwrap();
-    assert_eq!("doc", module.doc_comment_text());
+    assert_eq!("doc", module.doc_comment_text().unwrap());
+}
+
+#[test]
+fn test_doc_comment_preserves_indents() {
+    let file = SourceFile::parse(
+        r#"
+        /// doc1
+        /// ```
+        /// fn foo() {
+        ///     // ...
+        /// }
+        /// ```
+        mod foo {}
+        "#,
+    );
+    let module = file.syntax().descendants().find_map(Module::cast).unwrap();
+    assert_eq!(
+        "doc1\n```\nfn foo() {\n    // ...\n}\n```",
+        module.doc_comment_text().unwrap()
+    );
 }
diff --git a/crates/ra_syntax/src/ast/generated.rs b/crates/ra_syntax/src/ast/generated.rs
index 4f8723ae7..3ace6533c 100644
--- a/crates/ra_syntax/src/ast/generated.rs
+++ b/crates/ra_syntax/src/ast/generated.rs
@@ -660,50 +660,6 @@ impl ToOwned for DynTraitType {
 
 impl DynTraitType {}
 
-// ElseBranch
-#[derive(Debug, PartialEq, Eq, Hash)]
-#[repr(transparent)]
-pub struct ElseBranch {
-    pub(crate) syntax: SyntaxNode,
-}
-unsafe impl TransparentNewType for ElseBranch {
-    type Repr = rowan::SyntaxNode<RaTypes>;
-}
-
-#[derive(Debug, Clone, Copy, PartialEq, Eq)]
-pub enum ElseBranchKind<'a> {
-    Block(&'a Block),
-    IfExpr(&'a IfExpr),
-}
-
-impl AstNode for ElseBranch {
-    fn cast(syntax: &SyntaxNode) -> Option<&Self> {
-        match syntax.kind() {
-            | BLOCK
-            | IF_EXPR => Some(ElseBranch::from_repr(syntax.into_repr())),
-            _ => None,
-        }
-    }
-    fn syntax(&self) -> &SyntaxNode { &self.syntax }
-}
-
-impl ToOwned for ElseBranch {
-    type Owned = TreeArc<ElseBranch>;
-    fn to_owned(&self) -> TreeArc<ElseBranch> { TreeArc::cast(self.syntax.to_owned()) }
-}
-
-impl ElseBranch {
-    pub fn kind(&self) -> ElseBranchKind {
-        match self.syntax.kind() {
-            BLOCK => ElseBranchKind::Block(Block::cast(&self.syntax).unwrap()),
-            IF_EXPR => ElseBranchKind::IfExpr(IfExpr::cast(&self.syntax).unwrap()),
-            _ => unreachable!(),
-        }
-    }
-}
-
-impl ElseBranch {}
-
 // EnumDef
 #[derive(Debug, PartialEq, Eq, Hash)]
 #[repr(transparent)]
diff --git a/crates/ra_syntax/src/grammar/expressions.rs b/crates/ra_syntax/src/grammar/expressions.rs
index 1604d9b5a..d27eb8b7e 100644
--- a/crates/ra_syntax/src/grammar/expressions.rs
+++ b/crates/ra_syntax/src/grammar/expressions.rs
@@ -45,7 +45,6 @@ pub(crate) fn block(p: &mut Parser) {
 
     while !p.at(EOF) && !p.at(R_CURLY) {
         match p.current() {
-            LET_KW => let_stmt(p),
             // test nocontentexpr
             // fn foo(){
             //     ;;;some_expr();;;;{;;;};;;;Ok(())
@@ -55,41 +54,54 @@ pub(crate) fn block(p: &mut Parser) {
                 // test block_items
                 // fn a() { fn b() {} }
                 let m = p.start();
-                match items::maybe_item(p, items::ItemFlavor::Mod) {
-                    items::MaybeItem::Item(kind) => {
-                        m.complete(p, kind);
-                    }
-                    items::MaybeItem::Modifiers => {
-                        m.abandon(p);
-                        p.error("expected an item");
-                    }
-                    // test pub_expr
-                    // fn foo() { pub 92; } //FIXME
-                    items::MaybeItem::None => {
-                        let is_blocklike = expressions::expr_stmt(p) == BlockLike::Block;
-                        if p.at(R_CURLY) {
+                let has_attrs = p.at(POUND);
+                attributes::outer_attributes(p);
+                if p.at(LET_KW) {
+                    let_stmt(p, m);
+                } else {
+                    match items::maybe_item(p, items::ItemFlavor::Mod) {
+                        items::MaybeItem::Item(kind) => {
+                            m.complete(p, kind);
+                        }
+                        items::MaybeItem::Modifiers => {
                             m.abandon(p);
-                        } else {
-                            // test no_semi_after_block
-                            // fn foo() {
-                            //     if true {}
-                            //     loop {}
-                            //     match () {}
-                            //     while true {}
-                            //     for _ in () {}
-                            //     {}
-                            //     {}
-                            //     macro_rules! test {
-                            //          () => {}
-                            //     }
-                            //     test!{}
-                            // }
-                            if is_blocklike {
-                                p.eat(SEMI);
+                            p.error("expected an item");
+                        }
+                        // test pub_expr
+                        // fn foo() { pub 92; } //FIXME
+                        items::MaybeItem::None => {
+                            if has_attrs {
+                                m.abandon(p);
+                                p.error(
+                                    "expected a let statement or an item after attributes in block",
+                                );
                             } else {
-                                p.expect(SEMI);
+                                let is_blocklike = expressions::expr_stmt(p) == BlockLike::Block;
+                                if p.at(R_CURLY) {
+                                    m.abandon(p);
+                                } else {
+                                    // test no_semi_after_block
+                                    // fn foo() {
+                                    //     if true {}
+                                    //     loop {}
+                                    //     match () {}
+                                    //     while true {}
+                                    //     for _ in () {}
+                                    //     {}
+                                    //     {}
+                                    //     macro_rules! test {
+                                    //          () => {}
+                                    //     }
+                                    //     test!{}
+                                    // }
+                                    if is_blocklike {
+                                        p.eat(SEMI);
+                                    } else {
+                                        p.expect(SEMI);
+                                    }
+                                    m.complete(p, EXPR_STMT);
+                                }
                             }
-                            m.complete(p, EXPR_STMT);
                         }
                     }
                 }
@@ -106,9 +118,8 @@ pub(crate) fn block(p: &mut Parser) {
     //     let c = 92;
     //     let d: i32 = 92;
     // }
-    fn let_stmt(p: &mut Parser) {
+    fn let_stmt(p: &mut Parser, m: Marker) {
         assert!(p.at(LET_KW));
-        let m = p.start();
         p.bump();
         patterns::pattern(p);
         if p.at(COLON) {
diff --git a/crates/ra_syntax/src/grammar/items.rs b/crates/ra_syntax/src/grammar/items.rs
index 265e84570..18039cd3f 100644
--- a/crates/ra_syntax/src/grammar/items.rs
+++ b/crates/ra_syntax/src/grammar/items.rs
@@ -36,6 +36,7 @@ pub(super) const ITEM_RECOVERY_SET: TokenSet = token_set![
 
 pub(super) fn item_or_macro(p: &mut Parser, stop_on_r_curly: bool, flavor: ItemFlavor) {
     let m = p.start();
+    attributes::outer_attributes(p);
     match maybe_item(p, flavor) {
         MaybeItem::Item(kind) => {
             m.complete(p, kind);
@@ -79,7 +80,6 @@ pub(super) enum MaybeItem {
 }
 
 pub(super) fn maybe_item(p: &mut Parser, flavor: ItemFlavor) -> MaybeItem {
-    attributes::outer_attributes(p);
     opt_visibility(p);
     if let Some(kind) = items_without_modifiers(p) {
         return MaybeItem::Item(kind);
diff --git a/crates/ra_syntax/tests/data/parser/ok/0044_let_attrs.rs b/crates/ra_syntax/tests/data/parser/ok/0044_let_attrs.rs
new file mode 100644
index 000000000..325a97aeb
--- /dev/null
+++ b/crates/ra_syntax/tests/data/parser/ok/0044_let_attrs.rs
@@ -0,0 +1,5 @@
+// https://github.com/rust-analyzer/rust-analyzer/issues/677
+fn main() {
+    #[cfg(feature = "backtrace")]
+    let exit_code = panic::catch_unwind(move || main());
+}
diff --git a/crates/ra_syntax/tests/data/parser/ok/0044_let_attrs.txt b/crates/ra_syntax/tests/data/parser/ok/0044_let_attrs.txt
new file mode 100644
index 000000000..1f52f699b
--- /dev/null
+++ b/crates/ra_syntax/tests/data/parser/ok/0044_let_attrs.txt
@@ -0,0 +1,73 @@
+SOURCE_FILE@[0; 166)
+  FN_DEF@[0; 165)
+    COMMENT@[0; 60)
+    WHITESPACE@[60; 61)
+    FN_KW@[61; 63)
+    WHITESPACE@[63; 64)
+    NAME@[64; 68)
+      IDENT@[64; 68) "main"
+    PARAM_LIST@[68; 70)
+      L_PAREN@[68; 69)
+      R_PAREN@[69; 70)
+    WHITESPACE@[70; 71)
+    BLOCK@[71; 165)
+      L_CURLY@[71; 72)
+      WHITESPACE@[72; 77)
+      LET_STMT@[77; 163)
+        ATTR@[77; 106)
+          POUND@[77; 78)
+          TOKEN_TREE@[78; 106)
+            L_BRACK@[78; 79)
+            IDENT@[79; 82) "cfg"
+            TOKEN_TREE@[82; 105)
+              L_PAREN@[82; 83)
+              IDENT@[83; 90) "feature"
+              WHITESPACE@[90; 91)
+              EQ@[91; 92)
+              WHITESPACE@[92; 93)
+              STRING@[93; 104)
+              R_PAREN@[104; 105)
+            R_BRACK@[105; 106)
+        WHITESPACE@[106; 111)
+        LET_KW@[111; 114)
+        WHITESPACE@[114; 115)
+        BIND_PAT@[115; 124)
+          NAME@[115; 124)
+            IDENT@[115; 124) "exit_code"
+        WHITESPACE@[124; 125)
+        EQ@[125; 126)
+        WHITESPACE@[126; 127)
+        CALL_EXPR@[127; 162)
+          PATH_EXPR@[127; 146)
+            PATH@[127; 146)
+              PATH@[127; 132)
+                PATH_SEGMENT@[127; 132)
+                  NAME_REF@[127; 132)
+                    IDENT@[127; 132) "panic"
+              COLONCOLON@[132; 134)
+              PATH_SEGMENT@[134; 146)
+                NAME_REF@[134; 146)
+                  IDENT@[134; 146) "catch_unwind"
+          ARG_LIST@[146; 162)
+            L_PAREN@[146; 147)
+            LAMBDA_EXPR@[147; 161)
+              MOVE_KW@[147; 151)
+              WHITESPACE@[151; 152)
+              PARAM_LIST@[152; 154)
+                PIPE@[152; 153)
+                PIPE@[153; 154)
+              WHITESPACE@[154; 155)
+              CALL_EXPR@[155; 161)
+                PATH_EXPR@[155; 159)
+                  PATH@[155; 159)
+                    PATH_SEGMENT@[155; 159)
+                      NAME_REF@[155; 159)
+                        IDENT@[155; 159) "main"
+                ARG_LIST@[159; 161)
+                  L_PAREN@[159; 160)
+                  R_PAREN@[160; 161)
+            R_PAREN@[161; 162)
+        SEMI@[162; 163)
+      WHITESPACE@[163; 164)
+      R_CURLY@[164; 165)
+  WHITESPACE@[165; 166)
diff --git a/crates/tools/src/bin/pre-commit.rs b/crates/tools/src/bin/pre-commit.rs
index bae3b26d3..e00bd0d3d 100644
--- a/crates/tools/src/bin/pre-commit.rs
+++ b/crates/tools/src/bin/pre-commit.rs
@@ -1,10 +1,9 @@
-use std::{
-    process::{Command},
-};
+use std::process::Command;
 
-use tools::{Result, run_rustfmt, run, project_root};
 use failure::bail;
 
+use tools::{Result, run_rustfmt, run, project_root};
+
 fn main() -> tools::Result<()> {
     run_rustfmt(tools::Overwrite)?;
     update_staged()
diff --git a/crates/tools/src/lib.rs b/crates/tools/src/lib.rs
index d404db214..311bcb4d8 100644
--- a/crates/tools/src/lib.rs
+++ b/crates/tools/src/lib.rs
@@ -1,7 +1,8 @@
 use std::{
+    fs,
+    collections::HashMap,
     path::{Path, PathBuf},
     process::{Command, Stdio},
-    fs::copy,
     io::{Error, ErrorKind}
 };
 
@@ -13,6 +14,10 @@ pub use teraron::{Mode, Overwrite, Verify};
 pub type Result<T> = std::result::Result<T, failure::Error>;
 
 pub const GRAMMAR: &str = "crates/ra_syntax/src/grammar.ron";
+const GRAMMAR_DIR: &str = "crates/ra_syntax/src/grammar";
+const OK_INLINE_TESTS_DIR: &str = "crates/ra_syntax/tests/data/parser/inline/ok";
+const ERR_INLINE_TESTS_DIR: &str = "crates/ra_syntax/tests/data/parser/inline/err";
+
 pub const SYNTAX_KINDS: &str = "crates/ra_syntax/src/syntax_kinds/generated.rs.tera";
 pub const AST: &str = "crates/ra_syntax/src/ast/generated.rs.tera";
 const TOOLCHAIN: &str = "stable";
@@ -130,9 +135,9 @@ pub fn install_format_hook() -> Result<()> {
     if !result_path.exists() {
         run("cargo build --package tools --bin pre-commit", ".")?;
         if cfg!(windows) {
-            copy("./target/debug/pre-commit.exe", result_path)?;
+            fs::copy("./target/debug/pre-commit.exe", result_path)?;
         } else {
-            copy("./target/debug/pre-commit", result_path)?;
+            fs::copy("./target/debug/pre-commit", result_path)?;
         }
     } else {
         return Err(Error::new(ErrorKind::AlreadyExists, "Git hook already created").into());
@@ -156,3 +161,98 @@ pub fn run_fuzzer() -> Result<()> {
         "./crates/ra_syntax",
     )
 }
+
+pub fn gen_tests(mode: Mode) -> Result<()> {
+    let tests = tests_from_dir(&project_root().join(Path::new(GRAMMAR_DIR)))?;
+    fn install_tests(tests: &HashMap<String, Test>, into: &str, mode: Mode) -> Result<()> {
+        let tests_dir = project_root().join(into);
+        if !tests_dir.is_dir() {
+            fs::create_dir_all(&tests_dir)?;
+        }
+        // ok is never actually read, but it needs to be specified to create a Test in existing_tests
+        let existing = existing_tests(&tests_dir, true)?;
+        for t in existing.keys().filter(|&t| !tests.contains_key(t)) {
+            panic!("Test is deleted: {}", t);
+        }
+
+        let mut new_idx = existing.len() + 1;
+        for (name, test) in tests {
+            let path = match existing.get(name) {
+                Some((path, _test)) => path.clone(),
+                None => {
+                    let file_name = format!("{:04}_{}.rs", new_idx, name);
+                    new_idx += 1;
+                    tests_dir.join(file_name)
+                }
+            };
+            teraron::update(&path, &test.text, mode)?;
+        }
+        Ok(())
+    }
+    install_tests(&tests.ok, OK_INLINE_TESTS_DIR, mode)?;
+    install_tests(&tests.err, ERR_INLINE_TESTS_DIR, mode)
+}
+
+#[derive(Default, Debug)]
+struct Tests {
+    pub ok: HashMap<String, Test>,
+    pub err: HashMap<String, Test>,
+}
+
+fn tests_from_dir(dir: &Path) -> Result<Tests> {
+    let mut res = Tests::default();
+    for entry in ::walkdir::WalkDir::new(dir) {
+        let entry = entry.unwrap();
+        if !entry.file_type().is_file() {
+            continue;
+        }
+        if entry.path().extension().unwrap_or_default() != "rs" {
+            continue;
+        }
+        process_file(&mut res, entry.path())?;
+    }
+    let grammar_rs = dir.parent().unwrap().join("grammar.rs");
+    process_file(&mut res, &grammar_rs)?;
+    return Ok(res);
+    fn process_file(res: &mut Tests, path: &Path) -> Result<()> {
+        let text = fs::read_to_string(path)?;
+
+        for (_, test) in collect_tests(&text) {
+            if test.ok {
+                if let Some(old_test) = res.ok.insert(test.name.clone(), test) {
+                    bail!("Duplicate test: {}", old_test.name)
+                }
+            } else {
+                if let Some(old_test) = res.err.insert(test.name.clone(), test) {
+                    bail!("Duplicate test: {}", old_test.name)
+                }
+            }
+        }
+        Ok(())
+    }
+}
+
+fn existing_tests(dir: &Path, ok: bool) -> Result<HashMap<String, (PathBuf, Test)>> {
+    let mut res = HashMap::new();
+    for file in fs::read_dir(dir)? {
+        let file = file?;
+        let path = file.path();
+        if path.extension().unwrap_or_default() != "rs" {
+            continue;
+        }
+        let name = {
+            let file_name = path.file_name().unwrap().to_str().unwrap();
+            file_name[5..file_name.len() - 3].to_string()
+        };
+        let text = fs::read_to_string(&path)?;
+        let test = Test {
+            name: name.clone(),
+            text,
+            ok,
+        };
+        if let Some(old) = res.insert(name, (path, test)) {
+            println!("Duplicate test: {:?}", old);
+        }
+    }
+    Ok(res)
+}
diff --git a/crates/tools/src/main.rs b/crates/tools/src/main.rs
index d6eabce6c..c3e293911 100644
--- a/crates/tools/src/main.rs
+++ b/crates/tools/src/main.rs
@@ -1,30 +1,13 @@
-use std::{
-    collections::HashMap,
-    fs,
-    path::{Path, PathBuf},
-};
-
-use clap::{App, Arg, SubCommand};
-use failure::bail;
+use clap::{App, SubCommand};
 
 use tools::{
-    collect_tests, generate,install_format_hook, run, run_rustfmt,
-    Mode, Overwrite, Result, Test, Verify, project_root, run_fuzzer
+    generate, gen_tests, install_format_hook, run, run_rustfmt,
+    Overwrite, Result, run_fuzzer,
 };
 
-const GRAMMAR_DIR: &str = "crates/ra_syntax/src/grammar";
-const OK_INLINE_TESTS_DIR: &str = "crates/ra_syntax/tests/data/parser/inline/ok";
-const ERR_INLINE_TESTS_DIR: &str = "crates/ra_syntax/tests/data/parser/inline/err";
-
 fn main() -> Result<()> {
     let matches = App::new("tasks")
         .setting(clap::AppSettings::SubcommandRequiredElseHelp)
-        .arg(
-            Arg::with_name("verify")
-                .long("--verify")
-                .help("Verify that generated code is up-to-date")
-                .global(true),
-        )
         .subcommand(SubCommand::with_name("gen-syntax"))
         .subcommand(SubCommand::with_name("gen-tests"))
         .subcommand(SubCommand::with_name("install-code"))
@@ -32,19 +15,14 @@ fn main() -> Result<()> {
         .subcommand(SubCommand::with_name("format-hook"))
         .subcommand(SubCommand::with_name("fuzz-tests"))
         .get_matches();
-    let mode = if matches.is_present("verify") {
-        Verify
-    } else {
-        Overwrite
-    };
     match matches
         .subcommand_name()
         .expect("Subcommand must be specified")
     {
         "install-code" => install_code_extension()?,
-        "gen-tests" => gen_tests(mode)?,
+        "gen-tests" => gen_tests(Overwrite)?,
         "gen-syntax" => generate(Overwrite)?,
-        "format" => run_rustfmt(mode)?,
+        "format" => run_rustfmt(Overwrite)?,
         "format-hook" => install_format_hook()?,
         "fuzz-tests" => run_fuzzer()?,
         _ => unreachable!(),
@@ -52,101 +30,6 @@ fn main() -> Result<()> {
     Ok(())
 }
 
-fn gen_tests(mode: Mode) -> Result<()> {
-    let tests = tests_from_dir(Path::new(GRAMMAR_DIR))?;
-    fn install_tests(tests: &HashMap<String, Test>, into: &str, mode: Mode) -> Result<()> {
-        let tests_dir = project_root().join(into);
-        if !tests_dir.is_dir() {
-            fs::create_dir_all(&tests_dir)?;
-        }
-        // ok is never actually read, but it needs to be specified to create a Test in existing_tests
-        let existing = existing_tests(&tests_dir, true)?;
-        for t in existing.keys().filter(|&t| !tests.contains_key(t)) {
-            panic!("Test is deleted: {}", t);
-        }
-
-        let mut new_idx = existing.len() + 1;
-        for (name, test) in tests {
-            let path = match existing.get(name) {
-                Some((path, _test)) => path.clone(),
-                None => {
-                    let file_name = format!("{:04}_{}.rs", new_idx, name);
-                    new_idx += 1;
-                    tests_dir.join(file_name)
-                }
-            };
-            teraron::update(&path, &test.text, mode)?;
-        }
-        Ok(())
-    }
-    install_tests(&tests.ok, OK_INLINE_TESTS_DIR, mode)?;
-    install_tests(&tests.err, ERR_INLINE_TESTS_DIR, mode)
-}
-
-#[derive(Default, Debug)]
-struct Tests {
-    pub ok: HashMap<String, Test>,
-    pub err: HashMap<String, Test>,
-}
-
-fn tests_from_dir(dir: &Path) -> Result<Tests> {
-    let mut res = Tests::default();
-    for entry in ::walkdir::WalkDir::new(dir) {
-        let entry = entry.unwrap();
-        if !entry.file_type().is_file() {
-            continue;
-        }
-        if entry.path().extension().unwrap_or_default() != "rs" {
-            continue;
-        }
-        process_file(&mut res, entry.path())?;
-    }
-    let grammar_rs = dir.parent().unwrap().join("grammar.rs");
-    process_file(&mut res, &grammar_rs)?;
-    return Ok(res);
-    fn process_file(res: &mut Tests, path: &Path) -> Result<()> {
-        let text = fs::read_to_string(path)?;
-
-        for (_, test) in collect_tests(&text) {
-            if test.ok {
-                if let Some(old_test) = res.ok.insert(test.name.clone(), test) {
-                    bail!("Duplicate test: {}", old_test.name)
-                }
-            } else {
-                if let Some(old_test) = res.err.insert(test.name.clone(), test) {
-                    bail!("Duplicate test: {}", old_test.name)
-                }
-            }
-        }
-        Ok(())
-    }
-}
-
-fn existing_tests(dir: &Path, ok: bool) -> Result<HashMap<String, (PathBuf, Test)>> {
-    let mut res = HashMap::new();
-    for file in fs::read_dir(dir)? {
-        let file = file?;
-        let path = file.path();
-        if path.extension().unwrap_or_default() != "rs" {
-            continue;
-        }
-        let name = {
-            let file_name = path.file_name().unwrap().to_str().unwrap();
-            file_name[5..file_name.len() - 3].to_string()
-        };
-        let text = fs::read_to_string(&path)?;
-        let test = Test {
-            name: name.clone(),
-            text,
-            ok,
-        };
-        if let Some(old) = res.insert(name, (path, test)) {
-            println!("Duplicate test: {:?}", old);
-        }
-    }
-    Ok(res)
-}
-
 fn install_code_extension() -> Result<()> {
     run("cargo install --path crates/ra_lsp_server --force", ".")?;
     if cfg!(windows) {
diff --git a/crates/tools/tests/cli.rs b/crates/tools/tests/cli.rs
index 2d238d9ea..2ee4b5223 100644
--- a/crates/tools/tests/cli.rs
+++ b/crates/tools/tests/cli.rs
@@ -1,15 +1,23 @@
-extern crate tools;
-
-use tools::{generate, run_rustfmt, Verify};
+use tools::{generate, gen_tests, run_rustfmt, Verify};
 
 #[test]
-fn verify_template_generation() {
+fn generated_grammar_is_fresh() {
     if let Err(error) = generate(Verify) {
         panic!("{}. Please update it by running `cargo gen-syntax`", error);
     }
 }
 
 #[test]
+fn generated_tests_are_fresh() {
+    if let Err(error) = gen_tests(Verify) {
+        panic!(
+            "{}. Please update tests by running `cargo gen-tests`",
+            error
+        );
+    }
+}
+
+#[test]
 fn check_code_formatting() {
     if let Err(error) = run_rustfmt(Verify) {
         panic!(