4 files changed, 66 insertions, 80 deletions

diff --git a/Cargo.lock b/Cargo.lock
index 8c28929ed..b1fef2e80 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -526,6 +526,7 @@ dependencies = [
  "base_db",
  "cfg",
  "either",
+ "expect-test",
  "la-arena",
  "log",
  "mbe",
diff --git a/crates/hir_expand/Cargo.toml b/crates/hir_expand/Cargo.toml
index 7bb40ba9b..f649ab925 100644
--- a/crates/hir_expand/Cargo.toml
+++ b/crates/hir_expand/Cargo.toml
@@ -25,3 +25,4 @@ mbe = { path = "../mbe", version = "0.0.0" }
 
 [dev-dependencies]
 test_utils = { path = "../test_utils" }
+expect-test = "1.1"
diff --git a/crates/hir_expand/src/builtin_derive.rs b/crates/hir_expand/src/builtin_derive.rs
index b7f1aae8f..dfdb9cf59 100644
--- a/crates/hir_expand/src/builtin_derive.rs
+++ b/crates/hir_expand/src/builtin_derive.rs
@@ -267,13 +267,14 @@ fn partial_ord_expand(
 #[cfg(test)]
 mod tests {
     use base_db::{fixture::WithFixture, CrateId, SourceDatabase};
+    use expect_test::{expect, Expect};
     use name::{known, Name};
 
     use crate::{test_db::TestDB, AstId, MacroCallId, MacroCallKind, MacroCallLoc};
 
     use super::*;
 
-    fn expand_builtin_derive(s: &str, name: Name) -> String {
+    fn expand_builtin_derive(ra_fixture: &str, name: Name) -> String {
         let expander = BuiltinDeriveExpander::find_by_name(&name).unwrap();
         let fixture = format!(
             r#"//- /main.rs crate:main deps:core
@@ -282,7 +283,7 @@ $0
 //- /lib.rs crate:core
 // empty
 "#,
-            s
+            ra_fixture
         );
 
         let (db, file_pos) = TestDB::with_position(&fixture);
@@ -314,66 +315,57 @@ $0
         parsed.text().to_string()
     }
 
+    fn check_derive(ra_fixture: &str, name: Name, expected: Expect) {
+        let expanded = expand_builtin_derive(ra_fixture, name);
+        expected.assert_eq(&expanded);
+    }
+
     #[test]
     fn test_copy_expand_simple() {
-        let expanded = expand_builtin_derive(
+        check_derive(
             r#"
-        #[derive(Copy)]
-        struct Foo;
-"#,
+            #[derive(Copy)]
+            struct Foo;
+            "#,
             known::Copy,
+            expect![["impl< >core::marker::CopyforFoo< >{}"]],
         );
-
-        assert_eq!(expanded, "impl< >core::marker::CopyforFoo< >{}");
     }
 
     #[test]
     fn test_copy_expand_with_type_params() {
-        let expanded = expand_builtin_derive(
+        check_derive(
             r#"
-        #[derive(Copy)]
-        struct Foo<A, B>;
-"#,
+            #[derive(Copy)]
+            struct Foo<A, B>;
+            "#,
             known::Copy,
-        );
-
-        assert_eq!(
-            expanded,
-            "impl<T0:core::marker::Copy,T1:core::marker::Copy>core::marker::CopyforFoo<T0,T1>{}"
+            expect![["impl<T0:core::marker::Copy,T1:core::marker::Copy>core::marker::CopyforFoo<T0,T1>{}"]],
         );
     }
 
     #[test]
     fn test_copy_expand_with_lifetimes() {
-        let expanded = expand_builtin_derive(
+        check_derive(
             r#"
-        #[derive(Copy)]
-        struct Foo<A, B, 'a, 'b>;
-"#,
+            #[derive(Copy)]
+            struct Foo<A, B, 'a, 'b>;
+            "#,
             known::Copy,
-        );
-
-        // We currently just ignore lifetimes
-
-        assert_eq!(
-            expanded,
-            "impl<T0:core::marker::Copy,T1:core::marker::Copy>core::marker::CopyforFoo<T0,T1>{}"
+            // We currently just ignore lifetimes
+            expect![["impl<T0:core::marker::Copy,T1:core::marker::Copy>core::marker::CopyforFoo<T0,T1>{}"]],
         );
     }
 
     #[test]
     fn test_clone_expand() {
-        let expanded = expand_builtin_derive(
+        check_derive(
             r#"
-        #[derive(Clone)]
-        struct Foo<A, B>;
-"#,
+            #[derive(Clone)]
+            struct Foo<A, B>;
+            "#,
             known::Clone,
-        );
-
-        assert_eq!(
-            expanded,
-            "impl<T0:core::clone::Clone,T1:core::clone::Clone>core::clone::CloneforFoo<T0,T1>{}"
+            expect![["impl<T0:core::clone::Clone,T1:core::clone::Clone>core::clone::CloneforFoo<T0,T1>{}"]],
         );
     }
 }
diff --git a/crates/hir_expand/src/builtin_macro.rs b/crates/hir_expand/src/builtin_macro.rs
index b34f1a4f2..2a79c892b 100644
--- a/crates/hir_expand/src/builtin_macro.rs
+++ b/crates/hir_expand/src/builtin_macro.rs
@@ -491,6 +491,7 @@ mod tests {
         MacroCallLoc,
     };
     use base_db::{fixture::WithFixture, SourceDatabase};
+    use expect_test::{expect, Expect};
     use std::sync::Arc;
     use syntax::ast::NameOwner;
 
@@ -574,87 +575,86 @@ mod tests {
         db.parse_or_expand(file_id).unwrap().to_string()
     }
 
+    fn check_expansion(ra_fixture: &str, expect: Expect) {
+        let expansion = expand_builtin_macro(ra_fixture);
+        expect.assert_eq(&expansion);
+    }
+
     #[test]
     fn test_column_expand() {
-        let expanded = expand_builtin_macro(
+        check_expansion(
             r#"
             #[rustc_builtin_macro]
             macro_rules! column {() => {}}
             column!()
             "#,
+            expect![["0"]],
         );
-
-        assert_eq!(expanded, "0");
     }
 
     #[test]
     fn test_line_expand() {
-        let expanded = expand_builtin_macro(
+        check_expansion(
             r#"
             #[rustc_builtin_macro]
             macro_rules! line {() => {}}
             line!()
             "#,
+            expect![["0"]],
         );
-
-        assert_eq!(expanded, "0");
     }
 
     #[test]
     fn test_stringify_expand() {
-        let expanded = expand_builtin_macro(
+        check_expansion(
             r#"
             #[rustc_builtin_macro]
             macro_rules! stringify {() => {}}
             stringify!(a b c)
             "#,
+            expect![["\"a b c\""]],
         );
-
-        assert_eq!(expanded, "\"a b c\"");
     }
 
     #[test]
     fn test_env_expand() {
-        let expanded = expand_builtin_macro(
+        check_expansion(
             r#"
             #[rustc_builtin_macro]
             macro_rules! env {() => {}}
             env!("TEST_ENV_VAR")
             "#,
+            expect![["\"__RA_UNIMPLEMENTED__\""]],
         );
-
-        assert_eq!(expanded, "\"__RA_UNIMPLEMENTED__\"");
     }
 
     #[test]
     fn test_option_env_expand() {
-        let expanded = expand_builtin_macro(
+        check_expansion(
             r#"
             #[rustc_builtin_macro]
             macro_rules! option_env {() => {}}
             option_env!("TEST_ENV_VAR")
             "#,
+            expect![["std::option::Option::None:: < &str>"]],
         );
-
-        assert_eq!(expanded, "std::option::Option::None:: < &str>");
     }
 
     #[test]
     fn test_file_expand() {
-        let expanded = expand_builtin_macro(
+        check_expansion(
             r#"
             #[rustc_builtin_macro]
             macro_rules! file {() => {}}
             file!()
             "#,
+            expect![[r#""""#]],
         );
-
-        assert_eq!(expanded, "\"\"");
     }
 
     #[test]
     fn test_assert_expand() {
-        let expanded = expand_builtin_macro(
+        check_expansion(
             r#"
             #[rustc_builtin_macro]
             macro_rules! assert {
@@ -663,14 +663,13 @@ mod tests {
             }
             assert!(true, "{} {:?}", arg1(a, b, c), arg2);
             "#,
+            expect![["{{(&(true), &(\"{} {:?}\"), &(arg1(a,b,c)), &(arg2),);}}"]],
         );
-
-        assert_eq!(expanded, "{{(&(true), &(\"{} {:?}\"), &(arg1(a,b,c)), &(arg2),);}}");
     }
 
     #[test]
     fn test_compile_error_expand() {
-        let expanded = expand_builtin_macro(
+        check_expansion(
             r#"
             #[rustc_builtin_macro]
             macro_rules! compile_error {
@@ -679,15 +678,14 @@ mod tests {
             }
             compile_error!("error!");
             "#,
+            // This expands to nothing (since it's in item position), but emits an error.
+            expect![[""]],
         );
-
-        // This expands to nothing (since it's in item position), but emits an error.
-        assert_eq!(expanded, "");
     }
 
     #[test]
     fn test_format_args_expand() {
-        let expanded = expand_builtin_macro(
+        check_expansion(
             r#"
             #[rustc_builtin_macro]
             macro_rules! format_args {
@@ -696,17 +694,15 @@ mod tests {
             }
             format_args!("{} {:?}", arg1(a, b, c), arg2);
             "#,
-        );
-
-        assert_eq!(
-            expanded,
-            r#"std::fmt::Arguments::new_v1(&[], &[std::fmt::ArgumentV1::new(&(arg1(a,b,c)),std::fmt::Display::fmt),std::fmt::ArgumentV1::new(&(arg2),std::fmt::Display::fmt),])"#
+            expect![[
+                r#"std::fmt::Arguments::new_v1(&[], &[std::fmt::ArgumentV1::new(&(arg1(a,b,c)),std::fmt::Display::fmt),std::fmt::ArgumentV1::new(&(arg2),std::fmt::Display::fmt),])"#
+            ]],
         );
     }
 
     #[test]
     fn test_format_args_expand_with_comma_exprs() {
-        let expanded = expand_builtin_macro(
+        check_expansion(
             r#"
             #[rustc_builtin_macro]
             macro_rules! format_args {
@@ -715,17 +711,15 @@ mod tests {
             }
             format_args!("{} {:?}", a::<A,B>(), b);
             "#,
-        );
-
-        assert_eq!(
-            expanded,
-            r#"std::fmt::Arguments::new_v1(&[], &[std::fmt::ArgumentV1::new(&(a::<A,B>()),std::fmt::Display::fmt),std::fmt::ArgumentV1::new(&(b),std::fmt::Display::fmt),])"#
+            expect![[
+                r#"std::fmt::Arguments::new_v1(&[], &[std::fmt::ArgumentV1::new(&(a::<A,B>()),std::fmt::Display::fmt),std::fmt::ArgumentV1::new(&(b),std::fmt::Display::fmt),])"#
+            ]],
         );
     }
 
     #[test]
     fn test_include_bytes_expand() {
-        let expanded = expand_builtin_macro(
+        check_expansion(
             r#"
             #[rustc_builtin_macro]
             macro_rules! include_bytes {
@@ -734,21 +728,19 @@ mod tests {
             }
             include_bytes("foo");
             "#,
+            expect![[r#"b"""#]],
         );
-
-        assert_eq!(expanded, r#"b"""#);
     }
 
     #[test]
     fn test_concat_expand() {
-        let expanded = expand_builtin_macro(
+        check_expansion(
             r##"
             #[rustc_builtin_macro]
             macro_rules! concat {}
             concat!("foo", "r", 0, r#"bar"#, false);
             "##,
+            expect![[r#""foor0barfalse""#]],
         );
-
-        assert_eq!(expanded, r#""foor0barfalse""#);
     }
 }