interleave whitespace between recursive let and module bindings (#1990)

* interleave whitespace between recursive let and module bindings

* Inline braces surrounding a Pexp_match as jsx child.

* Consistent with Prettier
* Wastes less whitespace

Before:
```reason
<div>
  {
    switch (color) {
    | Black => ReasonReact.string("black")
    | Red => ReasonReact.string("red")
    }
  }
</div>;
```

```reason
<div>
  {switch (color) {
   | Black => ReasonReact.string("black")
   | Red => ReasonReact.string("red")
   }}
</div>;
```

* Cleanup unused code

* fix esy build

formatTest/unit_tests/expected_output/whitespace.re

@@ -9,6 +9,35 @@ module Test = {
   let y = 34;
 };
 
+/** recursive let bindings */
+
+/* see below */
+
+let foo = "abc"
+and bar = "def"
+and baz = "ghi";
+
+/* with whitespace */
+
+let foo = "abc"
+
+and bar = "def"
+
+and baz = "ghi";
+
+/** with whitespace and attrs */
+
+/* -> */
+
+[@foo]
+let foo = "abc"
+
+[@bar]
+and bar = "def"
+
+[@baz]
+and baz = "ghi";
+
 module Comments = {
   let z = 1;
   /* comment *without* whitespace interleaved*/
@@ -172,6 +201,85 @@ module PatternMatching = {
     };
 };
 
+/** recursive modules without whitespace */
+module rec A: {
+  type t;
+  let a_fn: t => B.t;
+  let of_float: float => t;
+} = {
+  type t = int;
+  let a_fn = x => B.of_int(x);
+  let of_float = x => int_of_float(x);
+}
+/* no whitespace */
+and B: {
+  type t;
+  let another_fn: t => A.t;
+  let of_int: int => t;
+} = {
+  type t = float;
+  let another_fn = x => A.of_float(x);
+  let of_int = x => float_of_int(x);
+};
+
+/** recursive modules with whitespace */
+
+/* -> below */
+
+module rec A: {
+  type t;
+  let a_fn: t => B.t;
+  let of_float: float => t;
+} = {
+  type t = int;
+  let a_fn = x => B.of_int(x);
+  let of_float = x => int_of_float(x);
+}
+
+/** okok */
+
+/* lala */
+
+and B: {
+  type t;
+  let another_fn: t => A.t;
+  let of_int: int => t;
+} = {
+  type t = float;
+  let another_fn = x => A.of_float(x);
+  let of_int = x => float_of_int(x);
+};
+
+/** recursive modules with attrs */
+
+/* -> below */
+
+[@foo1]
+module rec A: {
+  type t;
+  let a_fn: t => B.t;
+  let of_float: float => t;
+} = {
+  type t = int;
+  let a_fn = x => B.of_int(x);
+  let of_float = x => int_of_float(x);
+}
+
+/** okok */
+
+/* lala */
+
+[@foo2]
+and B: {
+  type t;
+  let another_fn: t => A.t;
+  let of_int: int => t;
+} = {
+  type t = float;
+  let another_fn = x => A.of_float(x);
+  let of_int = x => float_of_int(x);
+};
+
 module EdgeCase = {
   let x = 1; /* a */
 

formatTest/unit_tests/expected_output/whitespace.rei

@@ -244,6 +244,28 @@ and X2: Y2;
 module rec X1: Y1
 and X2: Y2;
 
+/** rec modules with whitespace */
+
+/* -> */
+
+module rec X1: Y1
+
+and X2: Y2;
+
+/** rec modules with whitespace and attrs */
+
+/* -> */
+
+[@foo]
+module rec X1: Y1
+
+/** another one below */
+
+/* random comment */
+
+[@bar]
+and X2: Y2;
+
 /* notice the whitespace after the last signature item */
 
 /* this one has whitespace interleaved */

formatTest/unit_tests/input/whitespace.re

@@ -10,6 +10,35 @@ module Test = {
 
 };
 
+/** recursive let bindings */
+
+/* see below */
+
+let foo = "abc"
+and bar = "def"
+and baz = "ghi";
+
+/* with whitespace */
+
+let foo = "abc"
+
+and bar = "def"
+
+and baz = "ghi";
+
+/** with whitespace and attrs */
+
+/* -> */
+
+[@foo]
+let foo = "abc"
+
+[@bar]
+and bar = "def"
+
+[@baz]
+and baz = "ghi";
+
 module Comments = {
 
   let z = 1;
@@ -177,6 +206,61 @@ module PatternMatching = {
   };
 };
 
+/** recursive modules without whitespace */
+module rec A: {type t; let a_fn: t => B.t; let of_float: float => t;} = {
+  type t = int;
+  let a_fn = x => B.of_int(x);
+  let of_float = x => int_of_float(x);
+}
+/* no whitespace */
+and B: {type t; let another_fn: t => A.t; let of_int: int => t;} = {
+  type t = float;
+  let another_fn = x => A.of_float(x);
+  let of_int = x => float_of_int(x);
+};
+
+/** recursive modules with whitespace */
+
+/* -> below */
+
+module rec A: {type t; let a_fn: t => B.t; let of_float: float => t;} = {
+  type t = int;
+  let a_fn = x => B.of_int(x);
+  let of_float = x => int_of_float(x);
+}
+
+/** okok */
+
+/* lala */
+
+and B: {type t; let another_fn: t => A.t; let of_int: int => t;} = {
+  type t = float;
+  let another_fn = x => A.of_float(x);
+  let of_int = x => float_of_int(x);
+};
+
+/** recursive modules with attrs */
+
+/* -> below */
+
+[@foo1]
+module rec A: {type t; let a_fn: t => B.t; let of_float: float => t;} = {
+  type t = int;
+  let a_fn = x => B.of_int(x);
+  let of_float = x => int_of_float(x);
+}
+
+/** okok */
+
+/* lala */
+
+[@foo2]
+and B: {type t; let another_fn: t => A.t; let of_int: int => t;} = {
+  type t = float;
+  let another_fn = x => A.of_float(x);
+  let of_int = x => float_of_int(x);
+};
+
 module EdgeCase = {
   let x = 1; /* a */
 

formatTest/unit_tests/input/whitespace.rei

@@ -245,6 +245,29 @@ and X2: Y2;
 module rec X1: Y1
 and X2: Y2;
 
+
+/** rec modules with whitespace */
+
+/* -> */
+
+module rec X1: Y1
+
+and X2: Y2;
+
+/** rec modules with whitespace and attrs */
+
+/* -> */
+
+[@foo]
+module rec X1: Y1
+
+/** another one below */
+
+/* random comment */
+
+[@bar]
+and X2: Y2;
+
 /* notice the whitespace after the last signature item */
 
 /* this one has whitespace interleaved */