Test emitting let instead of var.

Fixes #856

Author: cristianoc

jscomp/build_tests/custom_namespace/src/demo.bs.js

@@ -1,7 +1,7 @@
 'use strict';
 
 
-var v = 42;
+let v = 42;
 
 exports.v = v;
 /* No side effect */

jscomp/build_tests/devonly/src/demo.bs.js

@@ -1,9 +1,9 @@
 'use strict';
 
-var Demo$Liba = require("liba/src/demo.bs.js");
-var Demo$Libb = require("libb/src/demo.bs.js");
+let Demo$Liba = require("liba/src/demo.bs.js");
+let Demo$Libb = require("libb/src/demo.bs.js");
 
-var v = Demo$Liba.v + Demo$Libb.v | 0;
+let v = Demo$Liba.v + Demo$Libb.v | 0;
 
 exports.v = v;
 /* No side effect */

jscomp/build_tests/devonly/src/depdemo.bs.js

@@ -1,8 +1,8 @@
 'use strict';
 
-var Demo$Namespace = require("./demo.bs.js");
+let Demo$Namespace = require("./demo.bs.js");
 
-var a = Demo$Namespace.v;
+let a = Demo$Namespace.v;
 
 exports.a = a;
 /* No side effect */

jscomp/build_tests/devonly/src2/hello.bs.js

@@ -26,7 +26,7 @@ let function_ = "function"
 
 let function_async ~async = if async then "async function" else "function"
 
-let var = "var" (* should be able to switch to [let] easily*)
+let var = "let" (* should be able to switch to [let] easily*)
 
 let return = "return"
 

jscomp/build_tests/devonly/src2/hellodep.bs.js

@@ -1,14 +1,14 @@
 'use strict';
 
-var Mt = require("./mt.js");
-var Caml_exceptions = require("../../lib/js/caml_exceptions.js");
-var Caml_js_exceptions = require("../../lib/js/caml_js_exceptions.js");
+let Mt = require("./mt.js");
+let Caml_exceptions = require("../../lib/js/caml_exceptions.js");
+let Caml_js_exceptions = require("../../lib/js/caml_js_exceptions.js");
 
-var suites = {
+let suites = {
   contents: /* [] */0
 };
 
-var test_id = {
+let test_id = {
   contents: 0
 };
 
@@ -18,7 +18,7 @@ function eq(loc, x, y) {
 
 eq("File \"406_primitive_test.ml\", line 18, characters 6-13", 32, 32);
 
-var backend_type = {
+let backend_type = {
   TAG: "Other",
   _0: "BS"
 };
@@ -29,9 +29,9 @@ eq("File \"406_primitive_test.ml\", line 29, characters 6-13", backend_type, {
     });
 
 function f(param) {
-  var A = /* @__PURE__ */Caml_exceptions.create("A");
+  let A = /* @__PURE__ */Caml_exceptions.create("A");
   try {
-    for(var i = 0; i <= 200; ++i){
+    for(let i = 0; i <= 200; ++i){
       if (i === 10) {
         throw {
               RE_EXN_ID: A,
@@ -44,7 +44,7 @@ function f(param) {
     return ;
   }
   catch (raw_exn){
-    var exn = Caml_js_exceptions.internalToOCamlException(raw_exn);
+    let exn = Caml_js_exceptions.internalToOCamlException(raw_exn);
     if (exn.RE_EXN_ID === A) {
       return ;
     }
@@ -54,9 +54,9 @@ function f(param) {
 
 Mt.from_pair_suites("406_primitive_test", suites.contents);
 
-var v = 32;
+let v = 32;
 
-var max_array_length = /* Max_wosize */2147483647;
+let max_array_length = /* Max_wosize */2147483647;
 
 exports.suites = suites;
 exports.test_id = test_id;

jscomp/build_tests/namespace/src/demo.bs.js

@@ -11,7 +11,7 @@ function construct(b) {
   }
 }
 
-var er = {};
+let er = {};
 
 exports.construct = construct;
 exports.er = er;

jscomp/build_tests/namespace/src/main.bs.js

@@ -1,17 +1,17 @@
 'use strict';
 
-var Js_promise2 = require("../../lib/js/js_promise2.js");
+let Js_promise2 = require("../../lib/js/js_promise2.js");
 
 async function nestedPromise(xxx) {
-  var xx = await xxx;
+  let xx = await xxx;
   Js_promise2.then(xx, (function (x) {
           return Promise.resolve((console.log("Promise2.then", x), undefined));
         }));
   Js_promise2.$$catch(xx, (function (x) {
           console.log("Promise2.catch_", x);
           return Promise.resolve(0);
         }));
-  var arg1 = function (x) {
+  let arg1 = function (x) {
     return Promise.resolve((console.log("Promise.then_", x), undefined));
   };
   xx.then(arg1);
@@ -22,9 +22,9 @@ async function create(x) {
   return x;
 }
 
-var xx = create(10);
+let xx = create(10);
 
-var xxx = create(xx);
+let xxx = create(xx);
 
 nestedPromise(xxx);
 

jscomp/build_tests/ns/src/demo.js

@@ -5,17 +5,17 @@ function foo(x, y) {
   return x + y | 0;
 }
 
-var z = 7;
+let z = 7;
 
 function bar(x, y) {
   return x + y | 0;
 }
 
-var b = 7;
+let b = 7;
 
-var w = 7;
+let w = 7;
 
-var a = 7;
+let a = 7;
 
 console.log(a);