8 files changed, 80 insertions, 0 deletions
diff --git a/src/test/ui/parser/fn-defined-using-def.rs b/src/test/ui/parser/fn-defined-using-def.rs
new file mode 100644
index 00000000000..21da34c47c9
--- /dev/null
+++ b/src/test/ui/parser/fn-defined-using-def.rs
@@ -0,0 +1,10 @@
+// Check what happens when `def` is used to define a function, instead of `fn`
+// edition:2021
+
+#![allow(dead_code)]
+
+def foo() {}
+//~^ ERROR expected one of `!` or `::`, found `foo`
+//~^^ HELP write `fn` instead of `def` to declare a function
+
+fn main() {}
diff --git a/src/test/ui/parser/fn-defined-using-def.stderr b/src/test/ui/parser/fn-defined-using-def.stderr
new file mode 100644
index 00000000000..f34329012a0
--- /dev/null
+++ b/src/test/ui/parser/fn-defined-using-def.stderr
@@ -0,0 +1,10 @@
+error: expected one of `!` or `::`, found `foo`
+  --> $DIR/fn-defined-using-def.rs:6:5
+   |
+LL | def foo() {}
+   | --- ^^^ expected one of `!` or `::`
+   | |
+   | help: write `fn` instead of `def` to declare a function
+
+error: aborting due to previous error
+
diff --git a/src/test/ui/parser/fn-defined-using-fun.rs b/src/test/ui/parser/fn-defined-using-fun.rs
new file mode 100644
index 00000000000..4f74605043e
--- /dev/null
+++ b/src/test/ui/parser/fn-defined-using-fun.rs
@@ -0,0 +1,10 @@
+// Check what happens when `fun` is used to define a function, instead of `fn`
+// edition:2021
+
+#![allow(dead_code)]
+
+fun foo() {}
+//~^ ERROR expected one of `!` or `::`, found `foo`
+//~^^ HELP write `fn` instead of `fun` to declare a function
+
+fn main() {}
diff --git a/src/test/ui/parser/fn-defined-using-fun.stderr b/src/test/ui/parser/fn-defined-using-fun.stderr
new file mode 100644
index 00000000000..2f6cfff350c
--- /dev/null
+++ b/src/test/ui/parser/fn-defined-using-fun.stderr
@@ -0,0 +1,10 @@
+error: expected one of `!` or `::`, found `foo`
+  --> $DIR/fn-defined-using-fun.rs:6:5
+   |
+LL | fun foo() {}
+   | --- ^^^ expected one of `!` or `::`
+   | |
+   | help: write `fn` instead of `fun` to declare a function
+
+error: aborting due to previous error
+
diff --git a/src/test/ui/parser/fn-defined-using-func.rs b/src/test/ui/parser/fn-defined-using-func.rs
new file mode 100644
index 00000000000..2dce96fdce0
--- /dev/null
+++ b/src/test/ui/parser/fn-defined-using-func.rs
@@ -0,0 +1,10 @@
+// Check what happens when `func` is used to define a function, instead of `fn`
+// edition:2021
+
+#![allow(dead_code)]
+
+func foo() {}
+//~^ ERROR expected one of `!` or `::`, found `foo`
+//~^^ HELP write `fn` instead of `func` to declare a function
+
+fn main() {}
diff --git a/src/test/ui/parser/fn-defined-using-func.stderr b/src/test/ui/parser/fn-defined-using-func.stderr
new file mode 100644
index 00000000000..355741e8949
--- /dev/null
+++ b/src/test/ui/parser/fn-defined-using-func.stderr
@@ -0,0 +1,10 @@
+error: expected one of `!` or `::`, found `foo`
+  --> $DIR/fn-defined-using-func.rs:6:6
+   |
+LL | func foo() {}
+   | ---- ^^^ expected one of `!` or `::`
+   | |
+   | help: write `fn` instead of `func` to declare a function
+
+error: aborting due to previous error
+
diff --git a/src/test/ui/parser/fn-defined-using-function.rs b/src/test/ui/parser/fn-defined-using-function.rs
new file mode 100644
index 00000000000..fd8782728e2
--- /dev/null
+++ b/src/test/ui/parser/fn-defined-using-function.rs
@@ -0,0 +1,10 @@
+// Check what happens when `function` is used to define a function, instead of `fn`
+// edition:2021
+
+#![allow(dead_code)]
+
+function foo() {}
+//~^ ERROR expected one of `!` or `::`, found `foo`
+//~^^ HELP write `fn` instead of `function` to declare a function
+
+fn main() {}
diff --git a/src/test/ui/parser/fn-defined-using-function.stderr b/src/test/ui/parser/fn-defined-using-function.stderr
new file mode 100644
index 00000000000..43c33a2cdd7
--- /dev/null
+++ b/src/test/ui/parser/fn-defined-using-function.stderr
@@ -0,0 +1,10 @@
+error: expected one of `!` or `::`, found `foo`
+  --> $DIR/fn-defined-using-function.rs:6:10
+   |
+LL | function foo() {}
+   | -------- ^^^ expected one of `!` or `::`
+   | |
+   | help: write `fn` instead of `function` to declare a function
+
+error: aborting due to previous error
+