rome · MichaReiser · Nov 16, 2022 · Nov 15, 2022 · Nov 15, 2022 · Nov 15, 2022
diff --git a/crates/rome_diagnostics_categories/src/categories.rs b/crates/rome_diagnostics_categories/src/categories.rs
@@ -76,6 +76,7 @@ define_dategories! {
 
     // nursery
     "lint/nursery/noBannedTypes":"https://docs.rome.tools/lint/rules/noBannedTypes",
+    "lint/nursery/noConditionalAssignment": "https://docs.rome.tools/lint/rules/noConditionalAssignment",
     "lint/nursery/noConstAssign": "https://docs.rome.tools/lint/rules/noConstAssign",
     "lint/nursery/noDupeKeys":"https://docs.rome.tools/lint/rules/noDupeKeys",
     "lint/nursery/noExplicitAny": "https://docs.rome.tools/lint/rules/noExplicitAny",

diff --git a/crates/rome_js_analyze/src/analyzers/nursery.rs b/crates/rome_js_analyze/src/analyzers/nursery.rs
diff --git a/crates/rome_js_analyze/src/analyzers/nursery/no_conditional_assignment.rs b/crates/rome_js_analyze/src/analyzers/nursery/no_conditional_assignment.rs
@@ -0,0 +1,102 @@
+use rome_analyze::context::RuleContext;
+use rome_analyze::{declare_rule, Ast, Rule, RuleDiagnostic};
+use rome_console::markup;
+use rome_js_syntax::*;
+use rome_rowan::{declare_node_union, AstNode};
+
+declare_rule! {
+    /// Disallow assignment operators in conditional expressions.
+    ///
+    /// ## Examples
+    ///
+    /// ### Invalid
+    ///
+    /// ```js,expect_diagnostic
+    /// var x;
+    /// if (x = 0) {
+    ///     var b = 1;
+    /// }
+    /// ```
+    ///
+    /// ```js,expect_diagnostic
+    /// function setHeight(someNode) {
+    ///     "use strict";
+    ///     do {
+    ///         someNode.height = "100px";
+    ///     } while (someNode = someNode.parentNode);
+    /// }
+    /// ```
+    ///
+    /// ### Valid
+    ///
+    /// ```js
+    /// var x;
+    /// if (x === 0) {
+    ///     var b = 1;
+    /// }
+    /// ```
+    ///
+    /// ```js
+    /// function setHeight(someNode) {
+    ///     "use strict";
+    ///     do {
+    ///         someNode.height = "100px";
+    ///     } while ((someNode = someNode.parentNode) !== null);
+    /// }
+    /// ```
+    ///
+    /// ```
+    pub(crate) NoConditionalAssignment {
+        version: "11.0.0",
+        name: "noConditionalAssignment",
+        recommended: false,
+    }
+}
+
+declare_node_union! {
+    pub(crate) ConditionalStatement = JsConditionalExpression | JsWhileStatement | JsDoWhileStatement | JsIfStatement | JsForStatement
+}
+
+impl Rule for NoConditionalAssignment {
+    type Query = Ast<ConditionalStatement>;
+    type State = JsAssignmentExpression;
+    type Signals = Option<Self::State>;
+    type Options = ();
+
+    fn run(ctx: &RuleContext<Self>) -> Self::Signals {
+        let stmt = ctx.query();
+        stmt.test()
+            .map(|it| it.omit_parentheses())
+            .and_then(into_js_assignment)
+    }
+
+    fn diagnostic(_ctx: &RuleContext<Self>, expr: &Self::State) -> Option<RuleDiagnostic> {
+        Some(RuleDiagnostic::new(
+            rule_category!(),
+            expr.syntax().text_trimmed_range(),
+            markup! {
+                "Expected a conditional expression and instead saw an assignment."
+            },
+        ))
+    }
+}
+
+fn into_js_assignment(expr: JsAnyExpression) -> Option<JsAssignmentExpression> {
+    if let JsAnyExpression::JsAssignmentExpression(e) = expr {
+        Some(e)
+    } else {
+        None
+    }
+}
+
+impl ConditionalStatement {
+    fn test(&self) -> Option<JsAnyExpression> {
+        match self {
+            Self::JsConditionalExpression(it) => it.test().ok(),
+            Self::JsWhileStatement(it) => it.test().ok(),
+            Self::JsDoWhileStatement(it) => it.test().ok(),
+            Self::JsIfStatement(it) => it.test().ok(),
+            Self::JsForStatement(it) => it.test(),
+        }
+    }
+}
diff --git a/crates/rome_js_analyze/tests/specs/nursery/noConditionalAssignment/invalid.js b/crates/rome_js_analyze/tests/specs/nursery/noConditionalAssignment/invalid.js
@@ -0,0 +1,21 @@
+var x; if (x = 0) { var b = 1; }
+var x; while (x = 0) { var b = 1; }
+var x = 0, y; do { y = x; } while (x = x + 1);
+var x; for(; x+=1 ;){};
+var x; if ((x) = (0));
+if (someNode || (someNode = parentNode)) { }
+while (someNode || (someNode = parentNode)) { }
+do { } while (someNode || (someNode = parentNode));
+for (; (typeof l === 'undefined' ? (l = 0) : l); i++) { }
+if (x = 0) { }
+while (x = 0) { }
+do { } while (x = x + 1);
+for(; x = y; ) { }
+if ((x = 0)) { }
+while ((x = 0)) { }
+do { } while ((x = x + 1));
+for(; (x = y); ) { }
+var x; var b = (x = 0) ? 1 : 0;
+var x; var b = x && (y = 0) ? 1 : 0;
+(((3496.29)).bkufyydt = 2e308) ? foo : bar;
+
diff --git a/crates/rome_js_analyze/tests/specs/nursery/noConditionalAssignment/invalid.js.snap b/crates/rome_js_analyze/tests/specs/nursery/noConditionalAssignment/invalid.js.snap
@@ -0,0 +1,252 @@
+---
+source: crates/rome_js_analyze/tests/spec_tests.rs
+expression: invalid.js
+---
+# Input
+```js
+var x; if (x = 0) { var b = 1; }
+var x; while (x = 0) { var b = 1; }
+var x = 0, y; do { y = x; } while (x = x + 1);
+var x; for(; x+=1 ;){};
+var x; if ((x) = (0));
+if (someNode || (someNode = parentNode)) { }
+while (someNode || (someNode = parentNode)) { }
+do { } while (someNode || (someNode = parentNode));
+for (; (typeof l === 'undefined' ? (l = 0) : l); i++) { }
+if (x = 0) { }
+while (x = 0) { }
+do { } while (x = x + 1);
+for(; x = y; ) { }
+if ((x = 0)) { }
+while ((x = 0)) { }
+do { } while ((x = x + 1));
+for(; (x = y); ) { }
+var x; var b = (x = 0) ? 1 : 0;
+var x; var b = x && (y = 0) ? 1 : 0;
+(((3496.29)).bkufyydt = 2e308) ? foo : bar;
+
+```
+
+# Diagnostics
+```
+invalid.js:1:12 lint/nursery/noConditionalAssignment ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
+
+  ! Expected a conditional expression and instead saw an assignment.
+
+  > 1 │ var x; if (x = 0) { var b = 1; }
+      │            ^^^^^
+    2 │ var x; while (x = 0) { var b = 1; }
+    3 │ var x = 0, y; do { y = x; } while (x = x + 1);
+
+
+```
+
+```
+invalid.js:2:15 lint/nursery/noConditionalAssignment ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
+
+  ! Expected a conditional expression and instead saw an assignment.
+
+    1 │ var x; if (x = 0) { var b = 1; }
+  > 2 │ var x; while (x = 0) { var b = 1; }
+      │               ^^^^^
+    3 │ var x = 0, y; do { y = x; } while (x = x + 1);
+    4 │ var x; for(; x+=1 ;){};
+
+
+```
+
+```
+invalid.js:3:36 lint/nursery/noConditionalAssignment ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
+
+  ! Expected a conditional expression and instead saw an assignment.
+
+    1 │ var x; if (x = 0) { var b = 1; }
+    2 │ var x; while (x = 0) { var b = 1; }
+  > 3 │ var x = 0, y; do { y = x; } while (x = x + 1);
+      │                                    ^^^^^^^^^
+    4 │ var x; for(; x+=1 ;){};
+    5 │ var x; if ((x) = (0));
+
+
+```
+
+```
+invalid.js:4:14 lint/nursery/noConditionalAssignment ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
+
+  ! Expected a conditional expression and instead saw an assignment.
+
+    2 │ var x; while (x = 0) { var b = 1; }
+    3 │ var x = 0, y; do { y = x; } while (x = x + 1);
+  > 4 │ var x; for(; x+=1 ;){};
+      │              ^^^^
+    5 │ var x; if ((x) = (0));
+    6 │ if (someNode || (someNode = parentNode)) { }
+
+
+```
+
+```
+invalid.js:5:12 lint/nursery/noConditionalAssignment ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
+
+  ! Expected a conditional expression and instead saw an assignment.
+
+    3 │ var x = 0, y; do { y = x; } while (x = x + 1);
+    4 │ var x; for(; x+=1 ;){};
+  > 5 │ var x; if ((x) = (0));
+      │            ^^^^^^^^^
+    6 │ if (someNode || (someNode = parentNode)) { }
+    7 │ while (someNode || (someNode = parentNode)) { }
+
+
+```
+
+```
+invalid.js:10:5 lint/nursery/noConditionalAssignment ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
+
+  ! Expected a conditional expression and instead saw an assignment.
+
+     8 │ do { } while (someNode || (someNode = parentNode));
+     9 │ for (; (typeof l === 'undefined' ? (l = 0) : l); i++) { }
+  > 10 │ if (x = 0) { }
+       │     ^^^^^
+    11 │ while (x = 0) { }
+    12 │ do { } while (x = x + 1);
+
+
+```
+
+```
+invalid.js:11:8 lint/nursery/noConditionalAssignment ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
+
+  ! Expected a conditional expression and instead saw an assignment.
+
+     9 │ for (; (typeof l === 'undefined' ? (l = 0) : l); i++) { }
+    10 │ if (x = 0) { }
+  > 11 │ while (x = 0) { }
+       │        ^^^^^
+    12 │ do { } while (x = x + 1);
+    13 │ for(; x = y; ) { }
+
+
+```
+
+```
+invalid.js:12:15 lint/nursery/noConditionalAssignment ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
+
+  ! Expected a conditional expression and instead saw an assignment.
+
+    10 │ if (x = 0) { }
+    11 │ while (x = 0) { }
+  > 12 │ do { } while (x = x + 1);
+       │               ^^^^^^^^^
+    13 │ for(; x = y; ) { }
+    14 │ if ((x = 0)) { }
+
+
+```
+
+```
+invalid.js:13:7 lint/nursery/noConditionalAssignment ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
+
+  ! Expected a conditional expression and instead saw an assignment.
+
+    11 │ while (x = 0) { }
+    12 │ do { } while (x = x + 1);
+  > 13 │ for(; x = y; ) { }
+       │       ^^^^^
+    14 │ if ((x = 0)) { }
+    15 │ while ((x = 0)) { }
+
+
+```
+
+```
+invalid.js:14:6 lint/nursery/noConditionalAssignment ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
+
+  ! Expected a conditional expression and instead saw an assignment.
+
+    12 │ do { } while (x = x + 1);
+    13 │ for(; x = y; ) { }
+  > 14 │ if ((x = 0)) { }
+       │      ^^^^^
+    15 │ while ((x = 0)) { }
+    16 │ do { } while ((x = x + 1));
+
+
+```
+
+```
+invalid.js:15:9 lint/nursery/noConditionalAssignment ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
+
+  ! Expected a conditional expression and instead saw an assignment.
+
+    13 │ for(; x = y; ) { }
+    14 │ if ((x = 0)) { }
+  > 15 │ while ((x = 0)) { }
+       │         ^^^^^
+    16 │ do { } while ((x = x + 1));
+    17 │ for(; (x = y); ) { }
+
+
+```
+
+```
+invalid.js:16:16 lint/nursery/noConditionalAssignment ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
+
+  ! Expected a conditional expression and instead saw an assignment.
+
+    14 │ if ((x = 0)) { }
+    15 │ while ((x = 0)) { }
+  > 16 │ do { } while ((x = x + 1));
+       │                ^^^^^^^^^
+    17 │ for(; (x = y); ) { }
+    18 │ var x; var b = (x = 0) ? 1 : 0;
+
+
+```
+
+```
+invalid.js:17:8 lint/nursery/noConditionalAssignment ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
+
+  ! Expected a conditional expression and instead saw an assignment.
+
+    15 │ while ((x = 0)) { }
+    16 │ do { } while ((x = x + 1));
+  > 17 │ for(; (x = y); ) { }
+       │        ^^^^^
+    18 │ var x; var b = (x = 0) ? 1 : 0;
+    19 │ var x; var b = x && (y = 0) ? 1 : 0;
+
+
+```
+
+```
+invalid.js:18:17 lint/nursery/noConditionalAssignment ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
+
+  ! Expected a conditional expression and instead saw an assignment.
+
+    16 │ do { } while ((x = x + 1));
+    17 │ for(; (x = y); ) { }
+  > 18 │ var x; var b = (x = 0) ? 1 : 0;
+       │                 ^^^^^
+    19 │ var x; var b = x && (y = 0) ? 1 : 0;
+    20 │ (((3496.29)).bkufyydt = 2e308) ? foo : bar;
+
+
+```
+
+```
+invalid.js:20:2 lint/nursery/noConditionalAssignment ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
+
+  ! Expected a conditional expression and instead saw an assignment.
+
+    18 │ var x; var b = (x = 0) ? 1 : 0;
+    19 │ var x; var b = x && (y = 0) ? 1 : 0;
+  > 20 │ (((3496.29)).bkufyydt = 2e308) ? foo : bar;
+       │  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+    21 │     
+
+
+```
+
+