Enforce newlines between operands of ternary expressions if the expression spans multiple lines (multiline-ternary) #1558

feross · 2020-10-21T23:42:03Z

https://eslint.org/docs/rules/multiline-ternary

Desired config:

/*eslint multiline-ternary: ["error", "always-multiline"]*/

JavaScript allows operands of ternary expressions to be separated by newlines, which can improve the readability of your program.

For example:

var foo = bar > baz ? value1 : value2;

The above can be rewritten as the following to improve readability and more clearly delineate the operands:

var foo = bar > baz ?
    value1 :
    value2;

Rule Details

This rule enforces or disallows newlines between operands of a ternary expression.
Note: The location of the operators is not enforced by this rule. Please see the operator-linebreak rule if you are interested in enforcing the location of the operators themselves.

always-multiline

Examples of incorrect code for this rule with the "always-multiline" option:

/*eslint multiline-ternary: ["error", "always-multiline"]*/

foo > bar ? value1 :
    value2;

foo > bar ?
    value1 : value2;

foo > bar &&
    bar > baz ? value1 : value2;

Examples of correct code for this rule with the "always-multiline" option:

/*eslint multiline-ternary: ["error", "always-multiline"]*/

foo > bar ? value1 : value2;

foo > bar ?
    value1 :
    value2;

foo > bar ?
    (baz > qux ? value1 : value2) :
    value3;

foo > bar ?
    (baz > qux ?
        value1 :
        value2) :
    value3;

foo > bar &&
    bar > baz ?
        value1 :
        value2;

The text was updated successfully, but these errors were encountered:

feross · 2020-10-22T00:02:15Z

This rule seems to have a bug, which I've filed against ESLint here: eslint/eslint#13782

feross · 2020-10-22T00:11:03Z

Nevermind, I was misunderstanding the rule.

feross · 2020-10-22T00:12:39Z

3% ecosystem impact.

1..210
# tests 210
# pass  204
# fail  6

PRs need to be sent to these packages:

LinusU · 2022-09-01T11:26:30Z

Sorry for dragging up such an old issue. My team just noticed this since we upgraded to ts-standard 11 today 😅

Just wanted to share some unfortunate diffs that this generated:

   </head>
   <body>
     <div id="slip">
-      ${printerName == null ? '' : `
+      ${printerName == null
+        ? ''
+        : `
         <div class="printer-name">
           ${escapeHtml(printerName)}
         </div>
       `}
 
-      ${!isCopy ? '' : `
+      ${!isCopy
+        ? ''
+        : `
         <div class="copy-header">
           <div class="copy-title">KOPIA</div>
           <div class="copy-date">${escapeHtml(formatDateTime(now, 'yyyy-MM-dd HH:mm:ss', timeZone))}</div>

         _created_at: requestTime,
         _id: id,
         _updated_at: requestTime,
-        employee: employee == null || employeeGroups == null ? null : {
-          _created_at: employee._created_at,
-          _id: employee._id,
-          _updated_at: employee._updated_at,
-          name: employee.name,
-          groups: employeeGroups
-        },
+        employee: employee == null || employeeGroups == null
+          ? null
+          : {
+              _created_at: employee._created_at,
+              _id: employee._id,
+              _updated_at: employee._updated_at,
+              name: employee.name,
+              groups: employeeGroups
+            },
         orderIntentId,
         paymentMethodId: paymentMethod._id,

       const html = await renderSlipFromOrder(restaurant, orders, printerQueue ?? null, isCopy ?? false, dataloader)
 
-      return html == null ? null : {
-        html,
-        needsPrinting: null,
-        printerQueueId: printerQueue?._id ?? null,
-        restaurantId: restaurant._id
-      }
+      return html == null
+        ? null
+        : {
+            html,
+            needsPrinting: null,
+            printerQueueId: printerQueue?._id ?? null,
+            restaurantId: restaurant._id
+          }
     }
   }
 }

-          ${servingLocation?.tableName == null || servingLocation.tableName === '' ? '' : `
+          ${servingLocation?.tableName == null || servingLocation.tableName === ''
+            ? ''
+            : `
             <div class="footer-text">Utlämnas till: ${escapeHtml(servingLocation.tableName)}</div>
           `}

         {
           $set: {
-            alternativeItems: patch.alternativeItems == null ? undefined : ({
-              alternativeItems: patch.alternativeItems?.map(item => ({
-                countableUsage: item.countableUsage ?? undefined,
-                isDefault: item.isDefault ?? false,
-                name: item.name,
-                productId: item.addonProductId ?? undefined
-              }))
-            }),
+            alternativeItems: patch.alternativeItems == null
+              ? undefined
+              : ({
+                  alternativeItems: patch.alternativeItems?.map(item => ({
+                    countableUsage: item.countableUsage ?? undefined,
+                    isDefault: item.isDefault ?? false,
+                    name: item.name,
+                    productId: item.addonProductId ?? undefined
+                  }))
+                }),
             forceChoice: patch.forceChoice ?? undefined,
             isCountable: patch.isCountable ?? undefined,
             maxChoices: patch.maxChoices ?? undefined,

feross added the enhancement label Oct 21, 2020

feross added this to the standard 15 milestone Oct 21, 2020

feross mentioned this issue Oct 21, 2020

Indentation/alignment within ternary branches (consequent/alternate) #927

Closed

feross closed this as completed in standard/eslint-config-standard@022e671 Oct 22, 2020

This was referenced Oct 31, 2020

Enforce conditional expression styles #1424

Closed

@getify/eslint-plugin-proper-ternary #1422

Closed

github-actions bot locked as resolved and limited conversation to collaborators Oct 26, 2021

standard unlocked this conversation Sep 1, 2022

github-actions bot locked as resolved and limited conversation to collaborators Sep 2, 2023

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Enforce newlines between operands of ternary expressions if the expression spans multiple lines (multiline-ternary) #1558

Enforce newlines between operands of ternary expressions if the expression spans multiple lines (multiline-ternary) #1558

feross commented Oct 21, 2020 •

edited

feross commented Oct 22, 2020

feross commented Oct 22, 2020

feross commented Oct 22, 2020 •

edited

LinusU commented Sep 1, 2022

Enforce newlines between operands of ternary expressions if the expression spans multiple lines (multiline-ternary) #1558

Enforce newlines between operands of ternary expressions if the expression spans multiple lines (multiline-ternary) #1558

Comments

feross commented Oct 21, 2020 • edited

Rule Details

always-multiline

feross commented Oct 22, 2020

feross commented Oct 22, 2020

feross commented Oct 22, 2020 • edited

LinusU commented Sep 1, 2022

feross commented Oct 21, 2020 •

edited

feross commented Oct 22, 2020 •

edited