1 files changed, 111 insertions, 0 deletions
diff --git a/tests/ui/resolve/suggest-path-instead-of-mod-dot-item.rs b/tests/ui/resolve/suggest-path-instead-of-mod-dot-item.rs
new file mode 100644
index 00000000000..d5d6b13d62c
--- /dev/null
+++ b/tests/ui/resolve/suggest-path-instead-of-mod-dot-item.rs
@@ -0,0 +1,111 @@
+// Beginners write `mod.item` when they should write `mod::item`.
+// This tests that we suggest the latter when we encounter the former.
+
+pub mod a {
+    pub const I: i32 = 1;
+
+    pub fn f() -> i32 { 2 }
+
+    pub mod b {
+        pub const J: i32 = 3;
+
+        pub fn g() -> i32 { 4 }
+    }
+}
+
+fn h1() -> i32 {
+    a.I
+    //~^ ERROR expected value, found module `a`
+    //~| HELP use the path separator
+}
+
+fn h2() -> i32 {
+    a.g()
+    //~^ ERROR expected value, found module `a`
+    //~| HELP use the path separator
+}
+
+fn h3() -> i32 {
+    a.b.J
+    //~^ ERROR expected value, found module `a`
+    //~| HELP use the path separator
+}
+
+fn h4() -> i32 {
+    a::b.J
+    //~^ ERROR expected value, found module `a::b`
+    //~| HELP a constant with a similar name exists
+    //~| HELP use the path separator
+}
+
+fn h5() {
+    a.b.f();
+    //~^ ERROR expected value, found module `a`
+    //~| HELP use the path separator
+    let v = Vec::new();
+    v.push(a::b);
+    //~^ ERROR expected value, found module `a::b`
+    //~| HELP a constant with a similar name exists
+}
+
+fn h6() -> i32 {
+    a::b.f()
+    //~^ ERROR expected value, found module `a::b`
+    //~| HELP a constant with a similar name exists
+    //~| HELP use the path separator
+}
+
+fn h7() {
+    a::b
+    //~^ ERROR expected value, found module `a::b`
+    //~| HELP a constant with a similar name exists
+}
+
+fn h8() -> i32 {
+    a::b()
+    //~^ ERROR expected function, found module `a::b`
+    //~| HELP a constant with a similar name exists
+}
+
+macro_rules! module {
+    () => {
+        a
+        //~^ ERROR expected value, found module `a`
+        //~| ERROR expected value, found module `a`
+    };
+}
+
+macro_rules! create {
+    (method) => {
+        a.f()
+        //~^ ERROR expected value, found module `a`
+        //~| HELP use the path separator
+    };
+    (field) => {
+        a.f
+        //~^ ERROR expected value, found module `a`
+        //~| HELP use the path separator
+    };
+}
+
+fn h9() {
+    //
+    // Note that if the receiver is a macro call, we do not want to suggest to replace
+    // `.` with `::` as that would be a syntax error.
+    // Since the receiver is a module and not a type, we cannot suggest to surround
+    // it with angle brackets.
+    //
+
+    module!().g::<()>(); // no `help` here!
+
+    module!().g; // no `help` here!
+
+    //
+    // Ensure that the suggestion is shown for expressions inside of macro definitions.
+    //
+
+    let _ = create!(method);
+    let _ = create!(field);
+}
+
+fn main() {}