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

mightyiam added this to The Standard Project Sep 16, 2023

mightyiam moved this to Done in The Standard Project Sep 16, 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

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feross commented Oct 22, 2020

feross commented Oct 22, 2020

feross commented Oct 22, 2020 •

edited

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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 Loading

Rule Details

always-multiline

feross commented Oct 22, 2020

feross commented Oct 22, 2020

feross commented Oct 22, 2020 • edited Loading

LinusU commented Sep 1, 2022

feross commented Oct 21, 2020 •

edited

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feross commented Oct 22, 2020 •

edited

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