feat(rome_js_analyze): noEmptyPattern (#2731)

crates/rome_js_analyze/src/analyzers/no_empty_pattern.rs

@@ -0,0 +1,83 @@
+use rome_analyze::{context::RuleContext, declare_rule, Rule, RuleCategory, RuleDiagnostic};
+use rome_console::markup;
+use rome_js_syntax::{JsArrayBindingPattern, JsObjectBindingPattern};
+use rome_rowan::{declare_node_union, AstNode, AstSeparatedList};
+
+declare_rule! {
+    /// Disallows empty destructuring patterns.
+    /// ## Examples
+    ///
+    /// ### Valid
+    /// The following cases are valid because they create new bindings.
+    ///
+    /// ```js
+    /// var {a = {}} = foo;
+    /// var {a, b = {}} = foo;
+    /// var {a = []} = foo;
+    /// function foo({a = {}}) {}
+    /// function foo({a = []}) {}
+    /// var [a] = foo;
+    /// ```
+    ///
+    /// ### Invalid
+    ///
+    /// ```js,expect_diagnostic
+    /// var {} = foo;
+    /// ```
+    ///
+    /// ```js,expect_diagnostic
+    /// var {a: {}} = foo;
+    /// ```
+    ///
+    /// ```js,expect_diagnostic
+    /// function foo({}) {}
+    /// ```
+    ///
+    pub(crate) NoEmptyPattern = "noEmptyPattern"
+}
+
+impl Rule for NoEmptyPattern {
+    const CATEGORY: RuleCategory = RuleCategory::Lint;
+
+    type Query = JsAnyBindPatternLike;
+    type State = ();
+
+    fn run(ctx: &RuleContext<Self>) -> Option<Self::State> {
+        match ctx.query() {
+            JsAnyBindPatternLike::JsArrayBindingPattern(array) => {
+                if array.elements().len() == 0 {
+                    Some(())
+                } else {
+                    None
+                }
+            }
+            JsAnyBindPatternLike::JsObjectBindingPattern(object) => {
+                if object.properties().len() == 0 {
+                    Some(())
+                } else {
+                    None
+                }
+            }
+        }
+    }
+
+    fn diagnostic(ctx: &RuleContext<Self>, _: &Self::State) -> Option<RuleDiagnostic> {
+        let node = ctx.query();
+        let node_type = match node {
+            JsAnyBindPatternLike::JsArrayBindingPattern(_) => "array",
+            JsAnyBindPatternLike::JsObjectBindingPattern(_) => "object",
+        };
+
+        Some(RuleDiagnostic::warning(
+            node.range(),
+            markup! {
+                "Unexpected empty "{node_type}" pattern."
+            },
+        ))
+    }
+}
+
+declare_node_union! {
+    /// enum of `JsObjectBindingPattern` and `JsArrayBindingPattern`
+    pub(crate) JsAnyBindPatternLike = JsArrayBindingPattern | JsObjectBindingPattern
+}

crates/rome_js_analyze/tests/specs/noEmptyPattern.js

@@ -0,0 +1,17 @@
+// valid
+var {a = {}} = foo;
+var {a, b = {}} = foo;
+var {a = []} = foo;
+function foo({a = {}}) {}
+function foo({a = []}) {}
+var [a] = foo;
+// invalid
+var {} = foo;
+var [] = foo;
+var {a: {}} = foo;
+var {a, b: {}} = foo;
+var {a: []} = foo;
+function foo({}) {};
+function foo([]) {};
+function foo({a: {}}) {};
+function foo({a: []}) {};

crates/rome_js_analyze/tests/specs/noEmptyPattern.js.snap

@@ -0,0 +1,118 @@
+---
+source: crates/rome_js_analyze/tests/spec_tests.rs
+assertion_line: 98
+expression: noEmptyPattern.js
+---
+# Input
+```js
+// valid
+var {a = {}} = foo;
+var {a, b = {}} = foo;
+var {a = []} = foo;
+function foo({a = {}}) {}
+function foo({a = []}) {}
+var [a] = foo;
+// invalid
+var {} = foo;
+var [] = foo;
+var {a: {}} = foo;
+var {a, b: {}} = foo;
+var {a: []} = foo;
+function foo({}) {};
+function foo([]) {};
+function foo({a: {}}) {};
+function foo({a: []}) {};
+```
+
+# Diagnostics
+```
+warning[noEmptyPattern]: Unexpected empty object pattern.
+  ┌─ noEmptyPattern.js:9:5
+  │
+9 │ var {} = foo;
+  │     --
+
+
+```
+
+```
+warning[noEmptyPattern]: Unexpected empty array pattern.
+   ┌─ noEmptyPattern.js:10:5
+   │
+10 │ var [] = foo;
+   │     --
+
+
+```
+
+```
+warning[noEmptyPattern]: Unexpected empty object pattern.
+   ┌─ noEmptyPattern.js:11:9
+   │
+11 │ var {a: {}} = foo;
+   │         --
+
+
+```
+
+```
+warning[noEmptyPattern]: Unexpected empty object pattern.
+   ┌─ noEmptyPattern.js:12:12
+   │
+12 │ var {a, b: {}} = foo;
+   │            --
+
+
+```
+
+```
+warning[noEmptyPattern]: Unexpected empty array pattern.
+   ┌─ noEmptyPattern.js:13:9
+   │
+13 │ var {a: []} = foo;
+   │         --
+
+
+```
+
+```
+warning[noEmptyPattern]: Unexpected empty object pattern.
+   ┌─ noEmptyPattern.js:14:14
+   │
+14 │ function foo({}) {};
+   │              --
+
+
+```
+
+```
+warning[noEmptyPattern]: Unexpected empty array pattern.
+   ┌─ noEmptyPattern.js:15:14
+   │
+15 │ function foo([]) {};
+   │              --
+
+
+```
+
+```
+warning[noEmptyPattern]: Unexpected empty object pattern.
+   ┌─ noEmptyPattern.js:16:18
+   │
+16 │ function foo({a: {}}) {};
+   │                  --
+
+
+```
+
+```
+warning[noEmptyPattern]: Unexpected empty array pattern.
+   ┌─ noEmptyPattern.js:17:18
+   │
+17 │ function foo({a: []}) {};
+   │                  --
+
+
+```
+
+

website/src/docs/lint/rules/index.md

@@ -42,6 +42,13 @@ Disallow the use of the <code>delete</code> operator
 Require the use of <code>===</code> and <code>!==</code>
 </div>
 <div class="rule">
+<h3 data-toc-exclude id="noEmptyPattern">
+	<a href="/docs/lint/rules/noEmptyPattern">noEmptyPattern</a>
+	<a class="header-anchor" href="#noEmptyPattern"></a>
+</h3>
+Disallows empty destructuring patterns.
+</div>
+<div class="rule">
 <h3 data-toc-exclude id="noImplicitBoolean">
 	<a href="/docs/lint/rules/noImplicitBoolean">noImplicitBoolean</a>
 	<a class="header-anchor" href="#noImplicitBoolean"></a>

website/src/docs/lint/rules/noEmptyPattern.md

@@ -0,0 +1,62 @@
+---
+title: Lint Rule noEmptyPattern
+layout: layouts/rule.liquid
+---
+
+# noEmptyPattern
+
+Disallows empty destructuring patterns.
+
+## Examples
+
+### Valid
+
+The following cases are valid because they create new bindings.
+
+```jsx
+var {a = {}} = foo;
+var {a, b = {}} = foo;
+var {a = []} = foo;
+function foo({a = {}}) {}
+function foo({a = []}) {}
+var [a] = foo;
+```
+
+### Invalid
+
+```jsx
+var {} = foo;
+```
+
+{% raw %}<pre class="language-text"><code class="language-text"><span style="color: Orange;">warning</span><span style="color: Orange;">[</span><span style="color: Orange;">noEmptyPattern</span><span style="color: Orange;">]</span><em>: </em><em>Unexpected empty object pattern.</em>
+  <span style="color: rgb(38, 148, 255);">┌</span><span style="color: rgb(38, 148, 255);">─</span> noEmptyPattern.js:1:5
+  <span style="color: rgb(38, 148, 255);">│</span>
+<span style="color: rgb(38, 148, 255);">1</span> <span style="color: rgb(38, 148, 255);">│</span> var {} = foo;
+  <span style="color: rgb(38, 148, 255);">│</span>     <span style="color: rgb(38, 148, 255);">-</span><span style="color: rgb(38, 148, 255);">-</span>
+
+</code></pre>{% endraw %}
+
+```jsx
+var {a: {}} = foo;
+```
+
+{% raw %}<pre class="language-text"><code class="language-text"><span style="color: Orange;">warning</span><span style="color: Orange;">[</span><span style="color: Orange;">noEmptyPattern</span><span style="color: Orange;">]</span><em>: </em><em>Unexpected empty object pattern.</em>
+  <span style="color: rgb(38, 148, 255);">┌</span><span style="color: rgb(38, 148, 255);">─</span> noEmptyPattern.js:1:9
+  <span style="color: rgb(38, 148, 255);">│</span>
+<span style="color: rgb(38, 148, 255);">1</span> <span style="color: rgb(38, 148, 255);">│</span> var {a: {}} = foo;
+  <span style="color: rgb(38, 148, 255);">│</span>         <span style="color: rgb(38, 148, 255);">-</span><span style="color: rgb(38, 148, 255);">-</span>
+
+</code></pre>{% endraw %}
+
+```jsx
+function foo({}) {}
+```
+
+{% raw %}<pre class="language-text"><code class="language-text"><span style="color: Orange;">warning</span><span style="color: Orange;">[</span><span style="color: Orange;">noEmptyPattern</span><span style="color: Orange;">]</span><em>: </em><em>Unexpected empty object pattern.</em>
+  <span style="color: rgb(38, 148, 255);">┌</span><span style="color: rgb(38, 148, 255);">─</span> noEmptyPattern.js:1:14
+  <span style="color: rgb(38, 148, 255);">│</span>
+<span style="color: rgb(38, 148, 255);">1</span> <span style="color: rgb(38, 148, 255);">│</span> function foo({}) {}
+  <span style="color: rgb(38, 148, 255);">│</span>              <span style="color: rgb(38, 148, 255);">-</span><span style="color: rgb(38, 148, 255);">-</span>
+
+</code></pre>{% endraw %}
+