feat(linter/import): Implement max-dependencies

crates/oxc_linter/src/rules.rs

@@ -15,6 +15,7 @@ mod import {
     pub mod no_cycle;
     pub mod no_default_export;
     // pub mod no_deprecated;
+    pub mod max_dependencies;
     pub mod no_duplicates;
     pub mod no_named_as_default;
     pub mod no_named_as_default_member;
@@ -694,6 +695,7 @@ oxc_macros::declare_all_lint_rules! {
     react_perf::jsx_no_new_object_as_prop,
     import::default,
     import::export,
+    import::max_dependencies,
     import::named,
     import::namespace,
     import::no_amd,

crates/oxc_linter/src/rules/import/max_dependencies.rs

@@ -0,0 +1,202 @@
+use oxc_diagnostics::OxcDiagnostic;
+use oxc_macros::declare_oxc_lint;
+use oxc_span::Span;
+use serde_json::Value;
+
+use crate::{context::LintContext, rule::Rule};
+
+fn max_dependencies_diagnostic(x0: &str, span1: Span) -> OxcDiagnostic {
+    OxcDiagnostic::warn(format!("eslint-plugin-import(max-dependencies): {x0:?}"))
+        .with_help("Reduce the number of dependencies in this file")
+        .with_label(span1)
+}
+
+/// <https://github.com/import-js/eslint-plugin-import/blob/v2.29.1/docs/rules/max-dependencies.md>
+#[derive(Debug, Default, Clone)]
+pub struct MaxDependencies(Box<MaxDependenciesConfig>);
+
+#[derive(Debug, Clone)]
+pub struct MaxDependenciesConfig {
+    max: usize,
+    ignore_type_imports: bool,
+}
+
+impl std::ops::Deref for MaxDependencies {
+    type Target = MaxDependenciesConfig;
+
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+impl Default for MaxDependenciesConfig {
+    fn default() -> Self {
+        Self { max: 10, ignore_type_imports: false }
+    }
+}
+
+declare_oxc_lint!(
+    /// ### What it does
+    ///
+    /// Forbid modules to have too many dependencies (import or require statements).
+    ///
+    /// ### Why is this bad?
+    ///
+    /// This is a useful rule because a module with too many dependencies is a code smell, and
+    /// usually indicates the module is doing too much and/or should be broken up into smaller
+    /// modules.
+    ///
+    /// ### Example
+    ///
+    /// Given `{"max": 2}`
+    /// ```javascript
+    /// import a from './a';
+    /// import b from './b';
+    /// import c from './c';
+    /// ```
+
+    MaxDependencies,
+    pedantic,
+);
+
+impl Rule for MaxDependencies {
+    fn from_configuration(value: Value) -> Self {
+        let config = value.get(0);
+        if let Some(max) = config
+            .and_then(Value::as_number)
+            .and_then(serde_json::Number::as_u64)
+            .and_then(|v| usize::try_from(v).ok())
+        {
+            Self(Box::new(MaxDependenciesConfig { max, ignore_type_imports: false }))
+        } else {
+            let max = config
+                .and_then(|config| config.get("max"))
+                .and_then(Value::as_number)
+                .and_then(serde_json::Number::as_u64)
+                .map_or(10, |v| usize::try_from(v).unwrap_or(10));
+            let ignore_type_imports = config
+                .and_then(|config| config.get("ignoreTypeImports"))
+                .and_then(Value::as_bool)
+                .unwrap_or(false);
+
+            Self(Box::new(MaxDependenciesConfig { max, ignore_type_imports }))
+        }
+    }
+
+    fn run_once(&self, ctx: &LintContext<'_>) {
+        let module_record = ctx.module_record();
+        let mut module_count = module_record.import_entries.len();
+
+        let Some(entry) = module_record.import_entries.get(self.max) else {
+            return;
+        };
+
+        if self.ignore_type_imports {
+            let type_imports =
+                module_record.import_entries.iter().filter(|entry| entry.is_type).count();
+
+            module_count -= type_imports;
+        }
+
+        if module_count <= self.max {
+            return;
+        }
+
+        let error = format!(
+            "File has too many dependencies ({}). Maximum allowed is {}.",
+            module_count, self.max,
+        );
+        ctx.diagnostic(max_dependencies_diagnostic(&error, entry.module_request.span()));
+    }
+}
+
+#[test]
+fn test() {
+    use serde_json::json;
+
+    use crate::tester::Tester;
+
+    let pass = vec![
+        (
+            r"
+            import './foo.js';
+            ",
+            None,
+        ),
+        (
+            r"
+             import './foo.js';
+             import './bar.js';",
+            None,
+        ),
+        // (
+        //     r"
+        //      import './foo.js';
+        //      import './bar.js';
+        //      const a = require('./foo.js');
+        //      const b = require('./bar.js');
+        //     ",
+        //     Some(json!([{"max": 2}])),
+        // ),
+        (
+            r"
+                import {x, y, z} from './foo';
+            ",
+            None,
+        ),
+        (
+            r"
+            import type { x } from './foo';
+            import type { y } from './foo';
+            ",
+            Some(json!([{"max": 1, "ignoreTypeImports": true}])),
+        ),
+    ];
+
+    let fail = vec![
+        (
+            r"
+            import { x } from './foo';
+            import { y } from './foo';
+            import { z } from './bar';
+            ",
+            Some(json!([{"max": 1}])),
+        ),
+        (
+            r"
+            import { x } from './foo';
+            import { y } from './foo';
+            import { z } from './baz';
+            ",
+            Some(json!([{"max": 2}])),
+        ),
+        // (
+        //     r"
+        //     import { x } from './foo';
+        //     require('./bar'); const path = require('path');
+        //     import { z } from './baz';
+        //     ",
+        //     Some(json!([{"max": 2}])),
+        // ),
+        (
+            r"
+            import type { x } from './foo';
+            import type { y } from './foo';
+            ",
+            Some(json!([{"max": 1, }])),
+        ),
+        (
+            r"
+            import type { x } from './foo';
+            import type { y } from './foo';
+            import type { z } from './baz';
+            ",
+            Some(json!([{"max": 2, "ignoreTypeImports": false}])),
+        ),
+    ];
+
+    Tester::new(MaxDependencies::NAME, pass, fail)
+        .change_rule_path("index.ts")
+        .with_import_plugin(true)
+        .test_and_snapshot();
+}

crates/oxc_linter/src/snapshots/max_dependencies.snap

@@ -0,0 +1,38 @@
+---
+source: crates/oxc_linter/src/tester.rs
+---
+  ⚠ eslint-plugin-import(max-dependencies): "File has too many dependencies (3). Maximum allowed is 1."
+   ╭─[index.ts:3:31]
+ 2 │             import { x } from './foo';
+ 3 │             import { y } from './foo';
+   ·                               ───────
+ 4 │             import { z } from './bar';
+   ╰────
+  help: Reduce the number of dependencies in this file
+
+  ⚠ eslint-plugin-import(max-dependencies): "File has too many dependencies (3). Maximum allowed is 2."
+   ╭─[index.ts:4:31]
+ 3 │             import { y } from './foo';
+ 4 │             import { z } from './baz';
+   ·                               ───────
+ 5 │             
+   ╰────
+  help: Reduce the number of dependencies in this file
+
+  ⚠ eslint-plugin-import(max-dependencies): "File has too many dependencies (2). Maximum allowed is 1."
+   ╭─[index.ts:3:36]
+ 2 │             import type { x } from './foo';
+ 3 │             import type { y } from './foo';
+   ·                                    ───────
+ 4 │             
+   ╰────
+  help: Reduce the number of dependencies in this file
+
+  ⚠ eslint-plugin-import(max-dependencies): "File has too many dependencies (3). Maximum allowed is 2."
+   ╭─[index.ts:4:36]
+ 3 │             import type { y } from './foo';
+ 4 │             import type { z } from './baz';
+   ·                                    ───────
+ 5 │             
+   ╰────
+  help: Reduce the number of dependencies in this file