feat(biome_js_analyze): implement noExcessiveLinesPerFile

.changeset/wet-squids-agree.md

@@ -0,0 +1,13 @@
+---
+"@biomejs/biome": patch
+---
+
+Added the nursery lint rule [`noExcessiveLinesPerFile`](https://biomejs.dev/linter/rules/no-excessive-lines-per-file/).
+Biome now reports files that exceed a configurable line limit.
+
+```js
+// maxLines: 2
+const a = 1;
+const b = 2;
+const c = 3;
+```

crates/biome_js_analyze/src/lint/nursery.rs

@@ -10,6 +10,7 @@ pub mod no_deprecated_imports;
 pub mod no_duplicated_spread_props;
 pub mod no_empty_source;
 pub mod no_equals_to_null;
+pub mod no_excessive_lines_per_file;
 pub mod no_floating_promises;
 pub mod no_for_in;
 pub mod no_import_cycles;
@@ -57,4 +58,4 @@ pub mod use_spread;
 pub mod use_vue_consistent_define_props_declaration;
 pub mod use_vue_define_macros_order;
 pub mod use_vue_multi_word_component_names;
-declare_lint_group! { pub Nursery { name : "nursery" , rules : [self :: no_ambiguous_anchor_text :: NoAmbiguousAnchorText , self :: no_before_interactive_script_outside_document :: NoBeforeInteractiveScriptOutsideDocument , self :: no_continue :: NoContinue , self :: no_deprecated_imports :: NoDeprecatedImports , self :: no_duplicated_spread_props :: NoDuplicatedSpreadProps , self :: no_empty_source :: NoEmptySource , self :: no_equals_to_null :: NoEqualsToNull , self :: no_floating_promises :: NoFloatingPromises , self :: no_for_in :: NoForIn , self :: no_import_cycles :: NoImportCycles , self :: no_increment_decrement :: NoIncrementDecrement , self :: no_jsx_literals :: NoJsxLiterals , self :: no_jsx_props_bind :: NoJsxPropsBind , self :: no_leaked_render :: NoLeakedRender , self :: no_misused_promises :: NoMisusedPromises , self :: no_multi_assign :: NoMultiAssign , self :: no_multi_str :: NoMultiStr , self :: no_next_async_client_component :: NoNextAsyncClientComponent , self :: no_parameters_only_used_in_recursion :: NoParametersOnlyUsedInRecursion , self :: no_proto :: NoProto , self :: no_react_forward_ref :: NoReactForwardRef , self :: no_return_assign :: NoReturnAssign , self :: no_script_url :: NoScriptUrl , self :: no_shadow :: NoShadow , self :: no_sync_scripts :: NoSyncScripts , self :: no_ternary :: NoTernary , self :: no_undeclared_env_vars :: NoUndeclaredEnvVars , self :: no_unknown_attribute :: NoUnknownAttribute , self :: no_unnecessary_conditions :: NoUnnecessaryConditions , self :: no_unresolved_imports :: NoUnresolvedImports , self :: no_unused_expressions :: NoUnusedExpressions , self :: no_useless_catch_binding :: NoUselessCatchBinding , self :: no_useless_undefined :: NoUselessUndefined , self :: no_vue_data_object_declaration :: NoVueDataObjectDeclaration , self :: no_vue_duplicate_keys :: NoVueDuplicateKeys , self :: no_vue_reserved_keys :: NoVueReservedKeys , self :: no_vue_reserved_props :: NoVueReservedProps , self :: no_vue_setup_props_reactivity_loss :: NoVueSetupPropsReactivityLoss , self :: use_array_sort_compare :: UseArraySortCompare , self :: use_await_thenable :: UseAwaitThenable , self :: use_consistent_arrow_return :: UseConsistentArrowReturn , self :: use_destructuring :: UseDestructuring , self :: use_exhaustive_switch_cases :: UseExhaustiveSwitchCases , self :: use_explicit_type :: UseExplicitType , self :: use_find :: UseFind , self :: use_max_params :: UseMaxParams , self :: use_qwik_method_usage :: UseQwikMethodUsage , self :: use_qwik_valid_lexical_scope :: UseQwikValidLexicalScope , self :: use_regexp_exec :: UseRegexpExec , self :: use_sorted_classes :: UseSortedClasses , self :: use_spread :: UseSpread , self :: use_vue_consistent_define_props_declaration :: UseVueConsistentDefinePropsDeclaration , self :: use_vue_define_macros_order :: UseVueDefineMacrosOrder , self :: use_vue_multi_word_component_names :: UseVueMultiWordComponentNames ,] } }
+declare_lint_group! { pub Nursery { name : "nursery" , rules : [self :: no_ambiguous_anchor_text :: NoAmbiguousAnchorText , self :: no_before_interactive_script_outside_document :: NoBeforeInteractiveScriptOutsideDocument , self :: no_continue :: NoContinue , self :: no_deprecated_imports :: NoDeprecatedImports , self :: no_duplicated_spread_props :: NoDuplicatedSpreadProps , self :: no_empty_source :: NoEmptySource , self :: no_equals_to_null :: NoEqualsToNull , self :: no_excessive_lines_per_file :: NoExcessiveLinesPerFile , self :: no_floating_promises :: NoFloatingPromises , self :: no_for_in :: NoForIn , self :: no_import_cycles :: NoImportCycles , self :: no_increment_decrement :: NoIncrementDecrement , self :: no_jsx_literals :: NoJsxLiterals , self :: no_jsx_props_bind :: NoJsxPropsBind , self :: no_leaked_render :: NoLeakedRender , self :: no_misused_promises :: NoMisusedPromises , self :: no_multi_assign :: NoMultiAssign , self :: no_multi_str :: NoMultiStr , self :: no_next_async_client_component :: NoNextAsyncClientComponent , self :: no_parameters_only_used_in_recursion :: NoParametersOnlyUsedInRecursion , self :: no_proto :: NoProto , self :: no_react_forward_ref :: NoReactForwardRef , self :: no_return_assign :: NoReturnAssign , self :: no_script_url :: NoScriptUrl , self :: no_shadow :: NoShadow , self :: no_sync_scripts :: NoSyncScripts , self :: no_ternary :: NoTernary , self :: no_undeclared_env_vars :: NoUndeclaredEnvVars , self :: no_unknown_attribute :: NoUnknownAttribute , self :: no_unnecessary_conditions :: NoUnnecessaryConditions , self :: no_unresolved_imports :: NoUnresolvedImports , self :: no_unused_expressions :: NoUnusedExpressions , self :: no_useless_catch_binding :: NoUselessCatchBinding , self :: no_useless_undefined :: NoUselessUndefined , self :: no_vue_data_object_declaration :: NoVueDataObjectDeclaration , self :: no_vue_duplicate_keys :: NoVueDuplicateKeys , self :: no_vue_reserved_keys :: NoVueReservedKeys , self :: no_vue_reserved_props :: NoVueReservedProps , self :: no_vue_setup_props_reactivity_loss :: NoVueSetupPropsReactivityLoss , self :: use_array_sort_compare :: UseArraySortCompare , self :: use_await_thenable :: UseAwaitThenable , self :: use_consistent_arrow_return :: UseConsistentArrowReturn , self :: use_destructuring :: UseDestructuring , self :: use_exhaustive_switch_cases :: UseExhaustiveSwitchCases , self :: use_explicit_type :: UseExplicitType , self :: use_find :: UseFind , self :: use_max_params :: UseMaxParams , self :: use_qwik_method_usage :: UseQwikMethodUsage , self :: use_qwik_valid_lexical_scope :: UseQwikValidLexicalScope , self :: use_regexp_exec :: UseRegexpExec , self :: use_sorted_classes :: UseSortedClasses , self :: use_spread :: UseSpread , self :: use_vue_consistent_define_props_declaration :: UseVueConsistentDefinePropsDeclaration , self :: use_vue_define_macros_order :: UseVueDefineMacrosOrder , self :: use_vue_multi_word_component_names :: UseVueMultiWordComponentNames ,] } }

crates/biome_js_analyze/src/lint/nursery/no_excessive_lines_per_file.rs

@@ -0,0 +1,173 @@
+use biome_analyze::{
+    Ast, Rule, RuleDiagnostic, RuleSource, context::RuleContext, declare_lint_rule,
+};
+use biome_console::markup;
+use biome_js_syntax::{AnyJsRoot, JsSyntaxKind};
+use biome_rowan::AstNode;
+use biome_rule_options::no_excessive_lines_per_file::NoExcessiveLinesPerFileOptions;
+
+declare_lint_rule! {
+    /// Restrict the number of lines in a file.
+    ///
+    /// This rule checks the number of lines in a file and reports a diagnostic if it exceeds a specified limit.
+    /// Some people consider large files a code smell. Large files tend to do many things and can make it hard to follow what's going on.
+    /// Many coding style guides dictate a limit of the number of lines that a file can comprise of. This rule can help enforce that style.
+    ///
+    /// ## Examples
+    ///
+    /// ### Invalid
+    ///
+    /// The following example will show a diagnostic when `maxLines` is set to 2:
+    ///
+    /// ```json,options
+    /// {
+    ///     "options": {
+    ///        "maxLines": 2
+    ///     }
+    /// }
+    /// ```
+    /// ```js,expect_diagnostic,use_options
+    /// const a = 1;
+    /// const b = 2;
+    /// const c = 3;
+    /// ```
+    ///
+    /// ### Valid
+    ///
+    /// ```js
+    /// const a = 1;
+    /// const b = 2;
+    /// ```
+    ///
+    /// ## Options
+    ///
+    /// The following options are available:
+    ///
+    /// ### `maxLines`
+    ///
+    /// This option sets the maximum number of lines allowed in a file.
+    /// If the file exceeds this limit, a diagnostic will be reported.
+    ///
+    /// Default: `300`
+    ///
+    /// When `maxLines: 2`, the following file will be considered invalid:
+    /// ```json,options
+    /// {
+    ///     "options": {
+    ///        "maxLines": 2
+    ///     }
+    /// }
+    /// ```
+    /// ```js,expect_diagnostic,use_options
+    /// const a = 1;
+    /// const b = 2;
+    /// const c = 3;
+    /// ```
+    ///
+    /// ### `skipBlankLines`
+    ///
+    /// When this option is set to `true`, blank lines are not counted towards the maximum line limit.
+    /// This means that only lines with actual code or comments will be counted.
+    ///
+    /// Default: `false`
+    ///
+    /// When `maxLines: 3` and `skipBlankLines: true`, the following file will be considered valid
+    /// even though it has 5 total lines, because only 3 lines contain code:
+    /// ```json,options
+    /// {
+    ///     "options": {
+    ///        "maxLines": 3,
+    ///        "skipBlankLines": true
+    ///     }
+    /// }
+    /// ```
+    /// ```js,use_options
+    /// const a = 1;
+    ///
+    /// const b = 2;
+    ///
+    /// const c = 3;
+    /// ```
+    ///
+    /// ## Suppressions
+    ///
+    /// If you need to exceed the line limit in a specific file, you can suppress this rule
+    /// at the top of the file:
+    ///
+    /// ```json,options
+    /// {
+    ///     "options": {
+    ///         "maxLines": 2
+    ///     }
+    /// }
+    /// ```
+    /// ```js,use_options
+    /// // biome-ignore lint/nursery/noExcessiveLinesPerFile: generated file
+    /// const a = 1;
+    /// const b = 2;
+    /// const c = 3;
+    /// ```
+    ///
+    pub NoExcessiveLinesPerFile {
+        version: "next",
+        name: "noExcessiveLinesPerFile",
+        language: "js",
+        recommended: false,
+        sources: &[RuleSource::Eslint("max-lines").inspired()],
+    }
+}
+
+impl Rule for NoExcessiveLinesPerFile {
+    type Query = Ast<AnyJsRoot>;
+    type State = usize;
+    type Signals = Option<Self::State>;
+    type Options = NoExcessiveLinesPerFileOptions;
+
+    fn run(ctx: &RuleContext<Self>) -> Self::Signals {
+        let node = ctx.query();
+        let options = ctx.options();
+
+        let file_lines_count = node
+            .syntax()
+            .descendants()
+            .flat_map(|descendant| descendant.tokens().collect::<Vec<_>>())
+            .filter(|token| token.kind() != JsSyntaxKind::EOF)
+            .fold(0, |acc, token| {
+                if options.skip_blank_lines() {
+                    return acc + token.has_leading_newline() as usize;
+                };
+
+                acc + token
+                    .trim_trailing_trivia()
+                    .leading_trivia()
+                    .pieces()
+                    .filter(|piece| piece.is_newline())
+                    .count()
+            })
+            + 1; // Add 1 for the first line
+
+        if file_lines_count > options.max_lines().get().into() {
+            return Some(file_lines_count);
+        }
+
+        None
+    }
+
+    fn diagnostic(ctx: &RuleContext<Self>, state: &Self::State) -> Option<RuleDiagnostic> {
+        let node = ctx.query();
+        let options = ctx.options();
+
+        Some(
+            RuleDiagnostic::new(
+                rule_category!(),
+                node.range(),
+                markup! {
+                    "This file has too many lines ("{state}"). Maximum allowed is "{options.max_lines().to_string()}"."
+                },
+            )
+            .note(markup! {
+                "Consider splitting this file into smaller files."
+            }),
+        )
+    }
+}

crates/biome_js_analyze/tests/specs/nursery/noExcessiveLinesPerFile/empty.js.snap

@@ -0,0 +1,8 @@
+---
+source: crates/biome_js_analyze/tests/spec_tests.rs
+expression: empty.js
+---
+# Input
+```js
+
+```

crates/biome_js_analyze/tests/specs/nursery/noExcessiveLinesPerFile/empty.options.json

@@ -0,0 +1,15 @@
+{
+  "$schema": "../../../../../../packages/@biomejs/biome/configuration_schema.json",
+  "linter": {
+    "rules": {
+      "nursery": {
+        "noExcessiveLinesPerFile": {
+          "level": "error",
+          "options": {
+            "maxLines": 1
+          }
+        }
+      }
+    }
+  }
+}

crates/biome_js_analyze/tests/specs/nursery/noExcessiveLinesPerFile/invalid.js

@@ -0,0 +1,4 @@
+const a = 1;
+const b = 2;
+const c = 3;
+const d = 4;

crates/biome_js_analyze/tests/specs/nursery/noExcessiveLinesPerFile/invalid.js.snap

@@ -0,0 +1,33 @@
+---
+source: crates/biome_js_analyze/tests/spec_tests.rs
+expression: invalid.js
+---
+# Input
+```js
+const a = 1;
+const b = 2;
+const c = 3;
+const d = 4;
+
+```
+
+# Diagnostics
+```
+invalid.js:1:1 lint/nursery/noExcessiveLinesPerFile ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
+
+  i This file has too many lines (4). Maximum allowed is 2.
+
+  > 1 │ const a = 1;
+      │ ^^^^^^^^^^^^
+  > 2 │ const b = 2;
+  > 3 │ const c = 3;
+  > 4 │ const d = 4;
+      │ ^^^^^^^^^^^^
+    5 │ 
+
+  i Consider splitting this file into smaller files.
+
+  i This rule belongs to the nursery group, which means it is not yet stable and may change in the future. Visit https://biomejs.dev/linter/#nursery for more information.
+
+
+```

crates/biome_js_analyze/tests/specs/nursery/noExcessiveLinesPerFile/invalid.options.json

@@ -0,0 +1,15 @@
+{
+  "$schema": "../../../../../../packages/@biomejs/biome/configuration_schema.json",
+  "linter": {
+    "rules": {
+      "nursery": {
+        "noExcessiveLinesPerFile": {
+          "level": "error",
+          "options": {
+            "maxLines": 2
+          }
+        }
+      }
+    }
+  }
+}

crates/biome_js_analyze/tests/specs/nursery/noExcessiveLinesPerFile/invalidSkipBlankLines.js

@@ -0,0 +1,5 @@
+const a = 1;
+
+const b = 2;
+const c = 3;
+

crates/biome_js_analyze/tests/specs/nursery/noExcessiveLinesPerFile/invalidSkipBlankLines.js.snap

@@ -0,0 +1,34 @@
+---
+source: crates/biome_js_analyze/tests/spec_tests.rs
+expression: invalidSkipBlankLines.js
+---
+# Input
+```js
+const a = 1;
+
+const b = 2;
+const c = 3;
+
+
+```
+
+# Diagnostics
+```
+invalidSkipBlankLines.js:1:1 lint/nursery/noExcessiveLinesPerFile ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
+
+  i This file has too many lines (3). Maximum allowed is 2.
+
+  > 1 │ const a = 1;
+      │ ^^^^^^^^^^^^
+  > 2 │ 
+  > 3 │ const b = 2;
+  > 4 │ const c = 3;
+      │ ^^^^^^^^^^^^
+    5 │ 
+
+  i Consider splitting this file into smaller files.
+
+  i This rule belongs to the nursery group, which means it is not yet stable and may change in the future. Visit https://biomejs.dev/linter/#nursery for more information.
+
+
+```