Added tests for interface files and externals.

Author: cristianoc

CHANGELOG.md

@@ -18,6 +18,7 @@
 - Fix issue where spreading record types with optional labels would not have their labels preserved as optional. https://github.com/rescript-lang/rescript-compiler/pull/6154
 - Fix error location to be the type with the spreads when spreading record types with duplicate labels. https://github.com/rescript-lang/rescript-compiler/pull/6157
 - Disable warning on `@inline` attibute on uncurried functions. https://github.com/rescript-lang/rescript-compiler/pull/6152
+- Support doc comments on arguments of function types. https://github.com/rescript-lang/rescript-compiler/pull/6161
 
 # 11.0.0-alpha.3
 

res_syntax/tests/printer/expr/DocComments.res

@@ -2,3 +2,12 @@ let doc1: (/** ddd */ ~x: int) => int = (~x) => x + 1
 let doc2: @res.doc(" ddd ") int => int = x => x + 1
 let doc3: /** ddd */ int => int = x => x + 1
 let doc4: (/** ddd */ ~x: int, /** eee */ n) => int = (~x) => x + 1
+
+module M : {
+    let foo : (/** xxdoc */ ~x:int, /** yydoc */ ~y:int) => int
+} = {
+    let foo= (~x, ~y) => x+y
+}
+
+@val
+external ex : (/** ddd */ ~x: int, /** eee */ n) => int = "ex"

res_syntax/tests/printer/expr/expected/DocComments.res.txt

@@ -2,3 +2,12 @@ let doc1: (/** ddd */ ~x: int) => int = (~x) => x + 1
 let doc2: /** ddd */ int => int = x => x + 1
 let doc3: /** ddd */ int => int = x => x + 1
 let doc4: (/** ddd */ ~x: int, /** eee */ n) => int = (~x) => x + 1
+
+module M: {
+  let foo: (/** xxdoc */ ~x: int, /** yydoc */ ~y: int) => int
+} = {
+  let foo = (~x, ~y) => x + y
+}
+
+@val
+external ex: (/** ddd */ ~x: int, /** eee */ n) => int = "ex"