Bug 1828588 - [devtools] Better handle arrow functions. r=devtools-reviewers,ochameau.

Differential Revision: https://phabricator.services.mozilla.com/D175768

devtools/client/debugger/dist/pretty-print-worker.js

@@ -10239,6 +10239,9 @@
       if (token.type.label == "?") {
         return true;
       }
+      if (token.type.label == "=>") {
+        return true;
+      }
 
       return false;
     }
@@ -10273,6 +10276,9 @@
       if (lastTokenTypeLabel == "${") {
         return true;
       }
+      if (lastTokenTypeLabel == "=>") {
+        return true;
+      }
       return false;
     }
 

devtools/client/debugger/src/workers/pretty-print/pretty-fast.js

@@ -977,6 +977,9 @@ function needsSpaceAfter(token, lastToken) {
   if (token.type.label == "?") {
     return true;
   }
+  if (token.type.label == "=>") {
+    return true;
+  }
 
   return false;
 }
@@ -1011,6 +1014,9 @@ function needsSpaceBeforeLastToken(lastToken) {
   if (lastTokenTypeLabel == "${") {
     return true;
   }
+  if (lastTokenTypeLabel == "=>") {
+    return true;
+  }
   return false;
 }
 

devtools/client/debugger/src/workers/pretty-print/tests/__snapshots__/prettyFast.spec.js.snap

@@ -795,6 +795,51 @@ Array [
 ]
 `;
 
+exports[`Fat arrow function 1`] = `
+"const a = () => 42
+addEventListener('click', e => {
+  return false
+});
+const sum = (c, d) => c + d
+"
+`;
+
+exports[`Fat arrow function 2`] = `
+Array [
+  "(1, 0) -> (2, 6)",
+  "(1, 6) -> (2, 12)",
+  "(1, 8) -> (2, 14)",
+  "(1, 10) -> (2, 16)",
+  "(1, 11) -> (2, 17)",
+  "(1, 13) -> (2, 19)",
+  "(1, 16) -> (2, 22)",
+  "(2, 0) -> (3, 6)",
+  "(2, 16) -> (3, 22)",
+  "(2, 17) -> (3, 23)",
+  "(2, 24) -> (3, 30)",
+  "(2, 26) -> (3, 32)",
+  "(2, 28) -> (3, 34)",
+  "(2, 31) -> (3, 37)",
+  "(3, 2) -> (3, 39)",
+  "(3, 9) -> (3, 46)",
+  "(4, 0) -> (3, 52)",
+  "(4, 1) -> (3, 53)",
+  "(4, 2) -> (3, 54)",
+  "(5, 0) -> (4, 6)",
+  "(5, 6) -> (4, 12)",
+  "(5, 10) -> (4, 16)",
+  "(5, 12) -> (4, 18)",
+  "(5, 13) -> (4, 19)",
+  "(5, 14) -> (4, 20)",
+  "(5, 16) -> (4, 21)",
+  "(5, 17) -> (4, 22)",
+  "(5, 19) -> (4, 24)",
+  "(5, 22) -> (4, 27)",
+  "(5, 24) -> (4, 28)",
+  "(5, 26) -> (4, 29)",
+]
+`;
+
 exports[`For loop 1`] = `
 "for (var i = 0; i < n; i++) {
   console.log(i);

devtools/client/debugger/src/workers/pretty-print/tests/prettyFast.spec.js

@@ -400,6 +400,14 @@ const cases = [
       const x = ({thisIsAnotherVeryLongPropertyName: "but should not cause the paren to be a line delimiter"})
     `,
   },
+  {
+    name: "Fat arrow function",
+    input: `
+      const a = () => 42
+      addEventListener("click", e => { return false });
+      const sum = (c,d) => c+d
+    `,
+  },
 ];
 
 const includesOnly = cases.find(({ only }) => only);

devtools/client/debugger/test/mochitest/browser_dbg-pretty-print-inline-scripts.js

@@ -231,7 +231,7 @@ function getExpectedPrettyPrintedHtml() {
     <script>
 {
   'use strict';
-➤  document.querySelector('h1').addEventListener('mousedown', e=>{
+➤  document.querySelector('h1').addEventListener('mousedown', e => {
 ➤    console.log('mousedown on h1')
 ➤  })
 ➤}
@@ -247,7 +247,7 @@ function getExpectedPrettyPrintedHtml() {
   2,
   3
 ];
-➤y.map(i=>i * 2)
+➤y.map(i => i * 2)
 </script>
   </body>
 </html>

devtools/client/debugger/test/mochitest/browser_dbg-pretty-print-paused-anonymous.js

@@ -32,7 +32,7 @@ add_task(async function() {
     prettySourceValue.trim(),
     `debugger;
 var foo;
-document.addEventListener('click', e=>{
+document.addEventListener('click', e => {
   debugger;
 }, {
   once: true
@@ -80,9 +80,9 @@ document.addEventListener('click', e=>{
     prettyEvalSourceValue.trim(),
     `
 setTimeout(
-  () =>{
+  () => {
     debugger;
-    document.addEventListener('click', e=>{
+    document.addEventListener('click', e => {
       debugger;
     }, {
       once: true