fix(consistent-list-newline): when multiline nodes only have one item, line break should have same behavior (#40)

Co-authored-by: Anthony Fu <github@antfu.me>

Author: zzxming

src/rules/consistent-list-newline.test.ts

@@ -540,6 +540,117 @@ const invalid: InvalidTestCase[] = [
       }"
     `),
   },
+  {
+    code: $`
+      interface foo {
+      a:1}
+    `,
+    output: o => expect(o).toMatchInlineSnapshot(`
+      "interface foo {
+      a:1
+      }"
+    `),
+  },
+  {
+    code: $`
+      interface foo {a:1
+      }
+    `,
+    output: o => expect(o).toMatchInlineSnapshot(`
+      "interface foo {a:1}"
+    `),
+  },
+  {
+    code: $`
+      type foo = {
+      a:1}
+    `,
+    output: o => expect(o).toMatchInlineSnapshot(`
+      "type foo = {
+      a:1
+      }"
+    `),
+  },
+  {
+    code: $`
+      type foo = {a:1
+      }
+    `,
+    output: o => expect(o).toMatchInlineSnapshot(`
+      "type foo = {a:1}"
+    `),
+  },
+  {
+    code: $`
+      type foo = [
+      1]
+    `,
+    output: o => expect(o).toMatchInlineSnapshot(`
+      "type foo = [
+      1
+      ]"
+    `),
+  },
+  {
+    code: $`
+      type foo = [1
+      ]
+    `,
+    output: o => expect(o).toMatchInlineSnapshot(`
+      "type foo = [1]"
+    `),
+  },
+  {
+    code: $`
+      const foo = [
+      1]
+    `,
+    output: o => expect(o).toMatchInlineSnapshot(`
+      "const foo = [
+      1
+      ]"
+    `),
+  },
+  {
+    code: $`
+      const foo = {
+      a:1}
+    `,
+    output: o => expect(o).toMatchInlineSnapshot(`
+      "const foo = {
+      a:1
+      }"
+    `),
+  },
+  {
+    code: $`
+      const foo = {a:1
+      }
+    `,
+    output: o => expect(o).toMatchInlineSnapshot(`
+      "const foo = {a:1}"
+    `),
+  },
+  {
+    code: $`
+      function foo(a
+      ){}
+    `,
+    output: o => expect(o).toMatchInlineSnapshot(`
+      "function foo(a){}"
+    `),
+  },
+  {
+    code: $`
+      function foo(
+      a){}
+    `,
+    output: o => expect(o).toMatchInlineSnapshot(`
+      "function foo(
+      a
+      ){}"
+    `),
+  },
 ]
 
 run({

src/rules/consistent-list-newline.ts

@@ -1,4 +1,4 @@
-import type { TSESTree } from '@typescript-eslint/utils'
+import type { AST_NODE_TYPES, TSESTree } from '@typescript-eslint/utils'
 import type { RuleFix, RuleFixer, RuleListener } from '@typescript-eslint/utils/ts-eslint'
 import { createEslintRule } from '../utils'
 
@@ -68,6 +68,15 @@ export default createEslintRule<Options, MessageIds>({
   },
   defaultOptions: [{}],
   create: (context, [options = {}] = [{}]) => {
+    const multilineNodes = new Set([
+      'ArrayExpression',
+      'FunctionDeclaration',
+      'ObjectExpression',
+      'ObjectPattern',
+      'TSTypeLiteral',
+      'TSTupleType',
+      'TSInterfaceDeclaration',
+    ])
     function removeLines(fixer: RuleFixer, start: number, end: number, delimiter?: string): RuleFix {
       const range = [start, end] as const
       const code = context.sourceCode.text.slice(...range)
@@ -197,7 +206,7 @@ export default createEslintRule<Options, MessageIds>({
       }
       else if (mode === 'inline' && endLoc.line !== lastLine) {
         // If there is only one multiline item, we allow the closing bracket to be on the a different line
-        if (items.length === 1 && items[0].loc.start.line !== items[1]?.loc.start.line)
+        if (items.length === 1 && !(multilineNodes as Set<AST_NODE_TYPES>).has(node.type))
           return
         if (context.sourceCode.getCommentsAfter(lastItem).length > 0)
           return
@@ -211,7 +220,8 @@ export default createEslintRule<Options, MessageIds>({
               name: node.type,
             },
             * fix(fixer) {
-              yield removeLines(fixer, lastItem.range[1], endRange, getDelimiter(node, lastItem))
+              const delimiter = items.length === 1 ? '' : getDelimiter(node, lastItem)
+              yield removeLines(fixer, lastItem.range[1], endRange, delimiter)
             },
           })
         }