feat: add swiftlint

.gitignore

@@ -1,4 +1,5 @@
 bazel-*
+.DS_Store
 .bazelrc.user
 .idea/
 .ijwb/

README.md

@@ -50,14 +50,14 @@ Linters which are not language-specific:
 | Pkl                    | [pkl]                     |                                                         |
 | Protocol Buffer        | [buf]                     | [buf lint]                                              |
 | Python                 | [ruff]                    | [bandit], [flake8], [pydoclint], [pylint], [ruff], [ty] |
-| QML                    | [qmlformat]               | [qmllint]                                            |
+| QML                    | [qmlformat]               | [qmllint]                                               |
 | Ruby                   |                           | [RuboCop], [Standard]                                   |
 | Rust                   | [rustfmt]                 | [clippy]                                                |
 | SQL                    | [prettier-plugin-sql]     |                                                         |
 | Scala                  | [scalafmt]                |                                                         |
 | Shell                  | [shfmt]                   | [shellcheck]                                            |
 | Starlark               | [Buildifier]              | [Buildifier]                                            |
-| Swift                  | [SwiftFormat] (1)         |                                                         |
+| Swift                  | [SwiftFormat] (1)         | [SwiftLint] (1)                                         |
 | TOML                   | [taplo]                   |                                                         |
 | TSX                    | [Prettier]                | [ESLint]                                                |
 | TypeScript             | [Prettier]                | [ESLint]                                                |
@@ -75,6 +75,7 @@ Linters which are not language-specific:
 [buf lint]: https://buf.build/docs/lint/overview
 [eslint]: https://eslint.org/
 [swiftformat]: https://github.com/nicklockwood/SwiftFormat
+[swiftlint]: https://github.com/realm/SwiftLint
 [terraform]: https://github.com/hashicorp/terraform
 [buf]: https://docs.buf.build/format/usage
 [keep-sorted]: https://github.com/google/keep-sorted

examples/README.md

@@ -24,6 +24,7 @@ Each example is self-contained and shows:
 - `proto/` - Protocol Buffer formatting and linting with Buf
 - `starlark/` - Starlark formatting with Buildifier; linting with Buildifier
 - `qml/` - QML formatting with qmlformat; linting with qmllint
+- `swift/` - Swift formatting with SwiftFormat; linting with SwiftLint
 
 ## Multi-language Example
 

examples/swift/.bazelrc

@@ -0,0 +1,5 @@
+build:lint --aspects=//tools/lint:linters.bzl%swiftlint
+build:lint --aspects=//tools/lint:linters.bzl%swiftlint_nested_config
+build:lint --aspects=//tools/lint:linters.bzl%swiftlint_nested_deeper_nearest_config
+build:lint --aspects=//tools/lint:linters.bzl%swiftlint_nested_without_declared_config
+build:lint --aspects=//tools/lint:linters.bzl%swiftlint_nested_fix_config

examples/swift/.gitattributes

@@ -0,0 +1,3 @@
+# Keep the intentional SwiftLint fixtures stable when running aspect format.
+src/lintme.swift rules-lint-ignored
+src/nested_fix/lintme.swift rules-lint-ignored

examples/swift/.swiftlint.yml

@@ -0,0 +1,4 @@
+strict: true
+
+only_rules:
+  - function_name_whitespace

examples/swift/BUILD

@@ -0,0 +1,6 @@
+package(default_visibility = ["//visibility:public"])
+
+exports_files([
+    ".swiftlint.yml",
+    "SwiftLintBaseline.json",
+])

examples/swift/MODULE.aspect

@@ -0,0 +1,7 @@
+# Aspect Extension setup for CLI "lint" and "format" commands
+# This example is in rules_lint, so we use a local dependency.
+axl_local_dep(
+    name = "rules_lint",
+    path = "../..",
+    auto_use_tasks = True,
+)

examples/swift/MODULE.bazel

@@ -1,4 +1,4 @@
-"Bazel dependencies for Swift formatting example"
+"Bazel dependencies for Swift formatting and linting example"
 
 bazel_dep(name = "aspect_rules_lint")
 local_path_override(
@@ -10,3 +10,8 @@ local_path_override(
 format_tools = use_extension("@aspect_rules_lint//format:extensions.bzl", "tools")
 format_tools.swiftformat()
 use_repo(format_tools, "swiftformat", "swiftformat_mac")
+
+# Swift linter tools
+lint_tools = use_extension("@aspect_rules_lint//lint:extensions.bzl", "tools")
+lint_tools.swiftlint()
+use_repo(lint_tools, "swiftlint_binary")

examples/swift/README.md

@@ -1,26 +1,88 @@
-# Swift Formatting Example
+# Swift Formatting and Linting Example
 
-This example demonstrates how to set up formatting for Swift code using `rules_lint`.
+This example demonstrates how to set up formatting and linting for Swift code using `rules_lint`.
 
 ## Supported Tools
 
 ### Formatters
 
 - **SwiftFormat** - Code formatter for Swift
 
-Note: No Swift linter is currently available in rules_lint.
+### Linters
+
+- **SwiftLint** - Linter for Swift
 
 ## Setup
 
 1. Configure MODULE.bazel with required dependencies
 2. Create the MODULE.aspect file to register CLI tasks
 3. Configure Format Tools (add swiftformat)
-4. Configure Formatters
+4. Configure Lint Tools (add swiftlint)
+5. Configure Formatters and Linters
+
+- See `tools/format/BUILD` for how to set up the formatter
+- See `tools/lint/linters.bzl` for how to set up the linter aspect
+
+6. Perform formatting and linting using `aspect format` and `aspect lint`
+
+## SwiftLint Configuration
+
+SwiftLint policy such as enabled rules, severity, and human reporter should
+live in `.swiftlint.yml`. Bazel target membership determines which files the
+aspect lints. SwiftLint `excluded` entries are still honored, but `included`
+entries should not be used to narrow explicitly listed Bazel source files.
+
+The aspect only needs the binary and config labels for a typical setup:
 
-- See `tools/format/BUILD.bazel` for how to set up the formatter
+```starlark
+swiftlint = lint_swiftlint_aspect(
+    binary = Label("//tools/lint:swiftlint"),
+    configs = [Label("//:.swiftlint.yml")],
+)
+```
 
-5. Perform formatting using `aspect format`
+For target-specific nested `.swiftlint.yml` files, declare the main config
+first, then the nested configs, and set `config_mode = "nested"`:
+
+```starlark
+swiftlint = lint_swiftlint_aspect(
+    binary = Label("//tools/lint:swiftlint"),
+    configs = [
+        Label("//:.swiftlint.yml"),
+        Label("//src:nested/.swiftlint.yml"),
+    ],
+    config_mode = "nested",
+)
+```
+
+rules_lint selects the deepest declared nested config that contains all Swift
+sources in the target and passes only the main config plus that nearest nested
+config to SwiftLint with `--config`. This mirrors [SwiftLint's default nested
+configuration behavior](https://github.com/realm/SwiftLint#nested-configurations);
+intermediate ancestor configs are not accumulated for deeper files. SwiftLint
+does not auto-discover repository config files at execution time.
+
+Declare SwiftLint config hierarchy files in `configs`; prefer the aspect's
+`baseline` argument over a `baseline` entry in `.swiftlint.yml`:
+
+```starlark
+swiftlint_with_baseline = lint_swiftlint_aspect(
+    binary = Label("//tools/lint:swiftlint"),
+    configs = [Label("//:.swiftlint.yml")],
+    baseline = Label("//:SwiftLintBaseline.json"),
+)
+```
 
 ## Example Code
 
-See `src/hello.swift` for a simple example Swift file.
+See `src/formatme.swift` for a simple Swift file that SwiftFormat can format.
+See `src/lintme.swift` for a separate Swift file with an intentional SwiftLint
+violation. That lint fixture is marked `rules-lint-ignored` in `.gitattributes`
+so formatting the example does not erase the lint demo.
+
+## Configuration Files
+
+- `.swiftlint.yml` - SwiftLint configuration for the example
+- `src/nested/.swiftlint.yml` - nested SwiftLint configuration fixture
+- `src/nested/deeper/.swiftlint.yml` - nearest nested configuration fixture
+- `SwiftLintBaseline.json` - SwiftLint baseline used by the integration test

examples/swift/SwiftLintBaseline.json

@@ -0,0 +1,13 @@
+[
+  {
+    "violation": {
+      "ruleIdentifier": "function_name_whitespace",
+      "severity": "error",
+      "reason": "Too many spaces between 'func' and function name",
+      "ruleDescription": "There should be consistent whitespace before and after function names and generic parameters.",
+      "ruleName": "Function Name Whitespace",
+      "location": { "file": "src/lintme.swift", "character": 9, "line": 2 }
+    },
+    "text": "    func  printme() {"
+  }
+]

examples/swift/src/BUILD

@@ -1,6 +1,55 @@
 package(default_visibility = ["//visibility:public"])
 
+exports_files([
+    "nested/.swiftlint.yml",
+    "nested/deeper/.swiftlint.yml",
+    "nested_fix/.swiftlint.yml",
+])
+
+filegroup(
+    name = "lint",
+    srcs = ["lintme.swift"],
+    tags = ["swift"],
+)
+
+filegroup(
+    name = "baseline",
+    srcs = ["lintme.swift"],
+    tags = ["swift-baseline"],
+)
+
+filegroup(
+    name = "default_config",
+    srcs = ["lintme.swift"],
+    tags = ["swift-default-config"],
+)
+
+filegroup(
+    name = "verbose",
+    srcs = ["lintme.swift"],
+    tags = ["swift-verbose"],
+)
+
+filegroup(
+    name = "nested_config",
+    srcs = ["nested/lintme.swift"],
+    tags = ["swift-nested-config"],
+)
+
+filegroup(
+    name = "nested_deeper_nearest_config",
+    srcs = ["nested/deeper/nearest.swift"],
+    tags = ["swift-nested-deeper-nearest-config"],
+)
+
+filegroup(
+    name = "nested_without_declared_config",
+    srcs = ["nested/lintme.swift"],
+    tags = ["swift-nested-without-declared-config"],
+)
+
 filegroup(
-    name = "all",
-    srcs = ["hello.swift"],
+    name = "nested_fix_config",
+    srcs = ["nested_fix/lintme.swift"],
+    tags = ["swift-nested-fix-config"],
 )

examples/swift/src/formatme.swift

@@ -0,0 +1,3 @@
+struct FormatDemo {
+    let message="Hello, World!"
+}

examples/swift/src/hello.swift → examples/swift/src/lintme.swift

@@ -1,6 +1,5 @@
 class Controller {
-    func printme() {
+    func  printme() {
         print("Hello, World!")
     }
 }
-

examples/swift/src/nested/.swiftlint.yml

@@ -0,0 +1,4 @@
+strict: true
+
+only_rules:
+  - force_unwrapping

examples/swift/src/nested/deeper/.swiftlint.yml

@@ -0,0 +1,2 @@
+only_rules:
+  - empty_count

examples/swift/src/nested/deeper/nearest.swift

@@ -0,0 +1,2 @@
+let name: String? = "swift"
+print(name!)

examples/swift/src/nested/lintme.swift

@@ -0,0 +1,2 @@
+let name: String? = "swift"
+print(name!)

examples/swift/src/nested_fix/.swiftlint.yml

@@ -0,0 +1,2 @@
+only_rules:
+  - function_name_whitespace

examples/swift/src/nested_fix/lintme.swift

@@ -0,0 +1,5 @@
+class NestedFixController {
+    func  printme() {
+        print("Hello, World!")
+    }
+}

examples/swift/test/BUILD

@@ -0,0 +1,84 @@
+"Demonstrates how to enforce zero-lint-tolerance policy with tests"
+
+# buildifier: disable=bzl-visibility
+load("@aspect_rules_lint//lint/private:machine_report_testing.bzl", "report_test")
+load("//test:machine_output.bzl", "machine_swiftlint_nested_config_report", "machine_swiftlint_report", "machine_swiftlint_verbose_report")
+load(
+    "//tools/lint:linters.bzl",
+    "swiftlint_baseline_test",
+    "swiftlint_default_config_test",
+    "swiftlint_nested_config_test",
+    "swiftlint_nested_deeper_nearest_config_test",
+    "swiftlint_nested_without_declared_config_test",
+    "swiftlint_test",
+)
+
+package(default_visibility = ["//visibility:public"])
+
+swiftlint_test(
+    name = "swiftlint",
+    srcs = ["//src:lint"],
+    expected_exit_code = 2,
+)
+
+swiftlint_baseline_test(
+    name = "swiftlint_baseline",
+    srcs = ["//src:baseline"],
+)
+
+swiftlint_default_config_test(
+    name = "swiftlint_default_config",
+    srcs = ["//src:default_config"],
+)
+
+swiftlint_nested_config_test(
+    name = "swiftlint_nested_config",
+    srcs = ["//src:nested_config"],
+    expected_exit_code = 2,
+)
+
+swiftlint_nested_deeper_nearest_config_test(
+    name = "swiftlint_nested_deeper_nearest_config",
+    srcs = ["//src:nested_deeper_nearest_config"],
+)
+
+swiftlint_nested_without_declared_config_test(
+    name = "swiftlint_nested_without_declared_config",
+    srcs = ["//src:nested_without_declared_config"],
+)
+
+machine_swiftlint_report(
+    name = "machine_swiftlint_report",
+    src = "//src:lint",
+)
+
+machine_swiftlint_nested_config_report(
+    name = "machine_swiftlint_nested_config_report",
+    src = "//src:nested_config",
+)
+
+machine_swiftlint_verbose_report(
+    name = "machine_swiftlint_verbose_report",
+    src = "//src:verbose",
+)
+
+report_test(
+    name = "swiftlint_machine_output_test",
+    expected_tool = "SwiftLint",
+    expected_uri = "src/lintme.swift",
+    report = "machine_swiftlint_report",
+)
+
+report_test(
+    name = "swiftlint_nested_config_machine_output_test",
+    expected_tool = "SwiftLint",
+    expected_uri = "src/nested/lintme.swift",
+    report = "machine_swiftlint_nested_config_report",
+)
+
+report_test(
+    name = "swiftlint_verbose_machine_output_test",
+    expected_tool = "SwiftLint",
+    expected_uri = "src/lintme.swift",
+    report = "machine_swiftlint_verbose_report",
+)