prefer-spread: Report array.slice(0) (#1182)

Author: fisker

rules/prefer-spread.js

@@ -7,6 +7,7 @@ const {getParenthesizedRange} = require('./utils/parentheses');
 const shouldAddParenthesesToSpreadElementArgument = require('./utils/should-add-parentheses-to-spread-element-argument');
 const replaceNodeOrTokenAndSpacesBefore = require('./utils/replace-node-or-token-and-spaces-before');
 const removeSpacesAfter = require('./utils/remove-spaces-after');
+const isLiteralValue = require('./utils/is-literal-value');
 
 const ERROR_ARRAY_FROM = 'array-from';
 const ERROR_ARRAY_CONCAT = 'array-concat';
@@ -55,7 +56,8 @@ const arrayConcatCallSelector = [
 const arraySliceCallSelector = [
 	methodSelector({
 		name: 'slice',
-		length: 0
+		min: 0,
+		max: 1
 	}),
 	'[callee.object.type!="ArrayExpression"]'
 ].join('');
@@ -391,6 +393,11 @@ const create = context => {
 			context.report(problem);
 		},
 		[arraySliceCallSelector](node) {
+			const [firstArgument] = node.arguments;
+			if (firstArgument && !isLiteralValue(firstArgument, 0)) {
+				return;
+			}
+
 			context.report({
 				node: node.callee.property,
 				messageId: ERROR_ARRAY_SLICE,

test/package.mjs

@@ -21,7 +21,7 @@ const deprecatedRules = Object.entries(index.rules)
 
 const testSorted = (t, actualOrder, sourceName) => {
 	actualOrder = actualOrder.filter(x => !ignoredRules.includes(x));
-	const sortedOrder = actualOrder.slice(0).sort();
+	const sortedOrder = [...actualOrder].sort();
 
 	for (const [wantedIndex, name] of sortedOrder.entries()) {
 		const actualIndex = actualOrder.indexOf(name);

test/prefer-spread.mjs

@@ -278,7 +278,13 @@ test.snapshot({
 		'array.slice',
 		'array.slice(1)',
 		'array.slice(...[])',
-		'array.slice(0)',
+		'array.slice(...[0])',
+		'array.slice(0 + 0)',
+		'array.slice("")',
+		'array.slice(null)',
+		'const ZERO = 0;array.slice(ZERO)',
+		'array.slice(0, array.length)',
+		'array.slice(0, 0)',
 		'array.notSlice()',
 		// Why would someone write these
 		'[...foo].slice()',
@@ -298,6 +304,10 @@ test.snapshot({
 		`,
 		// `{String,TypedArray}#slice` are wrongly detected
 		'"".slice()',
-		'new Uint8Array([10, 20, 30, 40, 50]).slice()'
+		'new Uint8Array([10, 20, 30, 40, 50]).slice()',
+		'array.slice(0)',
+		'array.slice(0b0)',
+		'array.slice(0.00)',
+		'array.slice(0.00, )'
 	]
 });

test/snapshots/prefer-spread.mjs.md

@@ -1960,3 +1960,67 @@ Generated by [AVA](https://avajs.dev).
     > 1 | new Uint8Array([10, 20, 30, 40, 50]).slice()␊
         |                                      ^^^^^ Prefer the spread operator over \`Array#slice()\`.␊
     `
+
+## Invalid #10
+      1 | array.slice(0)
+
+> Output
+
+    `␊
+      1 | [...array]␊
+    `
+
+> Error 1/1
+
+    `␊
+    > 1 | array.slice(0)␊
+        |       ^^^^^ Prefer the spread operator over \`Array#slice()\`.␊
+    `
+
+## Invalid #11
+      1 | array.slice(0b0)
+
+> Output
+
+    `␊
+      1 | [...array]␊
+    `
+
+> Error 1/1
+
+    `␊
+    > 1 | array.slice(0b0)␊
+        |       ^^^^^ Prefer the spread operator over \`Array#slice()\`.␊
+    `
+
+## Invalid #12
+      1 | array.slice(0.00)
+
+> Output
+
+    `␊
+      1 | [...array]␊
+    `
+
+> Error 1/1
+
+    `␊
+    > 1 | array.slice(0.00)␊
+        |       ^^^^^ Prefer the spread operator over \`Array#slice()\`.␊
+    `
+
+## Invalid #13
+      1 | array.slice(0.00, )
+
+> Output
+
+    `␊
+      1 | [...array]␊
+    `
+
+> Error 1/1
+
+    `␊
+    > 1 | array.slice(0.00, )␊
+        |       ^^^^^ Prefer the spread operator over \`Array#slice()\`.␊
+    `