feat(swift): comprehensive Swift ecosystem filters (#848)

src/diff_cmd.rs

@@ -352,7 +352,11 @@ diff --git a/b.rs b/b.rs
         let result = compute_diff(&a_refs, &b_refs);
 
         // Should have ~167 changes (every 3rd line), all present
-        assert!(result.changes.len() > 100, "Expected 100+ changes, got {}", result.changes.len());
+        assert!(
+            result.changes.len() > 100,
+            "Expected 100+ changes, got {}",
+            result.changes.len()
+        );
         // No truncation — changes count matches what we generate
         assert!(!result.changes.is_empty());
     }

src/discover/registry.rs

@@ -1584,12 +1584,44 @@ mod tests {
             Classification::Supported {
                 rtk_equivalent: "rtk swift",
                 category: "Build",
-                estimated_savings_pct: 90.0,
+                estimated_savings_pct: 85.0,
                 status: RtkStatus::Existing,
             }
         ));
     }
 
+    #[test]
+    fn test_classify_swiftlint() {
+        assert!(matches!(
+            classify_command("swiftlint"),
+            Classification::Supported {
+                rtk_equivalent: "rtk swiftlint",
+                category: "Lint",
+                ..
+            }
+        ));
+    }
+
+    #[test]
+    fn test_classify_swiftformat() {
+        assert!(matches!(
+            classify_command("swiftformat ."),
+            Classification::Supported {
+                rtk_equivalent: "rtk swiftformat",
+                category: "Lint",
+                ..
+            }
+        ));
+    }
+
+    #[test]
+    fn test_rewrite_swift_package() {
+        assert_eq!(
+            rewrite_command("swift package resolve", &[]),
+            Some("rtk swift package resolve".into())
+        );
+    }
+
     #[test]
     fn test_rewrite_swift_test() {
         assert_eq!(

src/discover/rules.rs

@@ -79,7 +79,9 @@ pub const PATTERNS: &[&str] = &[
     r"^shellcheck\b",
     r"^shopify\s+theme\s+(push|pull)",
     r"^sops\b",
-    r"^swift\s+(build|test)\b",
+    r"^swift\s+(build|test|run|package)\b",
+    r"^swiftlint\b",
+    r"^swiftformat\b",
     r"^systemctl\s+status\b",
     r"^terraform\s+plan",
     r"^tofu\s+(fmt|init|plan|validate)(\s|$)",
@@ -600,7 +602,23 @@ pub const RULES: &[RtkRule] = &[
         rewrite_prefixes: &["swift"],
         category: "Build",
         savings_pct: 65.0,
-        subcmd_savings: &[("test", 90.0)],
+        subcmd_savings: &[("test", 85.0), ("run", 70.0), ("package", 80.0)],
+        subcmd_status: &[],
+    },
+    RtkRule {
+        rtk_cmd: "rtk swiftlint",
+        rewrite_prefixes: &["swiftlint"],
+        category: "Lint",
+        savings_pct: 75.0,
+        subcmd_savings: &[],
+        subcmd_status: &[],
+    },
+    RtkRule {
+        rtk_cmd: "rtk swiftformat",
+        rewrite_prefixes: &["swiftformat"],
+        category: "Lint",
+        savings_pct: 70.0,
+        subcmd_savings: &[],
         subcmd_status: &[],
     },
     RtkRule {

src/filters/swift-build.toml

@@ -6,6 +6,9 @@ strip_lines_matching = [
   "^\\s*$",
   "^Compiling ",
   "^Linking ",
+  "^\\[\\d+/\\d+\\] ",
+  "^Building for ",
+  "^Build of product ",
 ]
 match_output = [
   { pattern = "Build complete!", message = "ok (build complete)", unless = "warning:|error:" },

src/filters/swift-package.toml

@@ -0,0 +1,44 @@
+[filters.swift-package]
+description = "Compact swift package output — strip Fetching/Resolving noise, show summary"
+match_command = "^swift\\s+package\\s+(resolve|update)\\b"
+strip_ansi = true
+strip_lines_matching = [
+  "^\\s*$",
+  "^Fetching ",
+  "^Fetched ",
+  "^Computing version ",
+  "^Creating working copy ",
+  "^Working copy of ",
+  "^Cloning ",
+]
+match_output = [
+  { pattern = "^Resolved", message = "ok (dependencies resolved)" },
+]
+max_lines = 30
+on_empty = "ok (swift package: no output)"
+
+[[tests.swift-package]]
+name = "resolve strips fetching noise"
+input = """
+Fetching https://github.com/apple/swift-argument-parser from cache
+Fetching https://github.com/apple/swift-log from cache
+Fetched https://github.com/apple/swift-argument-parser from cache (0.42s)
+Fetched https://github.com/apple/swift-log from cache (0.38s)
+Computing version for https://github.com/apple/swift-argument-parser
+Computed https://github.com/apple/swift-argument-parser at 1.3.0 (0.01s)
+Computing version for https://github.com/apple/swift-log
+Computed https://github.com/apple/swift-log at 1.5.4 (0.01s)
+Resolved
+"""
+expected = "ok (dependencies resolved)"
+
+[[tests.swift-package]]
+name = "update with new versions shows computed lines"
+input = """
+Fetching https://github.com/apple/swift-argument-parser
+Fetched https://github.com/apple/swift-argument-parser (1.23s)
+Computing version for https://github.com/apple/swift-argument-parser
+Computed https://github.com/apple/swift-argument-parser at 1.4.0 (0.02s)
+Updated https://github.com/apple/swift-argument-parser (1.3.0 -> 1.4.0)
+"""
+expected = "Computed https://github.com/apple/swift-argument-parser at 1.4.0 (0.02s)\nUpdated https://github.com/apple/swift-argument-parser (1.3.0 -> 1.4.0)"

src/filters/swift-run.toml

@@ -0,0 +1,37 @@
+[filters.swift-run]
+description = "Compact swift run output — strip build noise, show application output"
+match_command = "^swift\\s+run\\b"
+strip_ansi = true
+strip_lines_matching = [
+  "^\\s*$",
+  "^Compiling ",
+  "^Linking ",
+  "^Build complete!",
+  "^\\[\\d+/\\d+\\] ",
+  "^Building for ",
+  "^Build of product ",
+]
+max_lines = 80
+on_empty = "ok (swift run: no output)"
+
+[[tests.swift-run]]
+name = "strips build noise, keeps app output"
+input = """
+Compiling MyApp main.swift
+Compiling MyApp Config.swift
+Linking MyApp
+Build complete!
+Hello, World!
+Processing 42 items...
+Done.
+"""
+expected = "Hello, World!\nProcessing 42 items...\nDone."
+
+[[tests.swift-run]]
+name = "build error passes through"
+input = """
+Compiling MyApp main.swift
+/Users/dev/MyApp/Sources/main.swift:3:5: error: cannot find 'foo' in scope
+error: build had 1 command failure
+"""
+expected = "/Users/dev/MyApp/Sources/main.swift:3:5: error: cannot find 'foo' in scope\nerror: build had 1 command failure"

src/filters/swift-test.toml

@@ -0,0 +1,69 @@
+[filters.swift-test]
+description = "Compact swift test output — strip passing tests, show failures and summary"
+match_command = "^swift\\s+test\\b"
+strip_ansi = true
+strip_lines_matching = [
+  "^\\s*$",
+  "^Compiling ",
+  "^Linking ",
+  "^Build complete!",
+  "^\\[\\d+/\\d+\\] ",
+  "^Building for ",
+  "^Build of product ",
+  "^Test Case .* passed ",
+  "^Test Case .* started\\.",
+  "^Test Suite .* started at ",
+  "^Test Suite .* passed at ",
+  "^\\t\\s*Executed \\d+ tests?, with 0 failures",
+  "^. Test run started",
+  "^. Testing Library",
+  "^. Test run with 0 tests",
+]
+match_output = [
+  { pattern = "^Executed \\d+ tests?, with 0 failures", message = "ok (all tests passed)", unless = "warning:|error:" },
+  { pattern = "Executed \\d+ tests?, with 0 failures", message = "ok (all tests passed)", unless = "warning:|error:" },
+]
+max_lines = 60
+on_empty = "ok (swift test: no output)"
+
+[[tests.swift-test]]
+name = "all tests pass — short-circuit to ok"
+input = """
+Compiling MyApp MyApp.swift
+Linking MyAppTests
+Build complete!
+Test Suite 'All tests' started at 2026-03-10 12:00:00
+Test Suite 'MyAppTests' started at 2026-03-10 12:00:00
+Test Case '-[MyAppTests testAddition]' passed (0.001 seconds).
+Test Case '-[MyAppTests testSubtraction]' passed (0.002 seconds).
+Test Suite 'MyAppTests' passed at 2026-03-10 12:00:01
+Executed 2 tests, with 0 failures in 0.003 seconds
+"""
+expected = "ok (all tests passed)"
+
+[[tests.swift-test]]
+name = "test failures shown with summary"
+input = """
+Compiling MyApp MyApp.swift
+Linking MyAppTests
+Build complete!
+Test Suite 'All tests' started at 2026-03-10 12:00:00
+Test Suite 'MyAppTests' started at 2026-03-10 12:00:00
+Test Case '-[MyAppTests testAddition]' passed (0.001 seconds).
+Test Case '-[MyAppTests testFailing]' failed (0.002 seconds).
+/Users/dev/MyApp/Tests/MyAppTests.swift:15: error: -[MyAppTests testFailing] : XCTAssertEqual failed: ("1") is not equal to ("2")
+Test Suite 'MyAppTests' failed at 2026-03-10 12:00:01
+Executed 2 tests, with 1 failure in 0.003 seconds
+"""
+expected = "Test Case '-[MyAppTests testFailing]' failed (0.002 seconds).\n/Users/dev/MyApp/Tests/MyAppTests.swift:15: error: -[MyAppTests testFailing] : XCTAssertEqual failed: (\"1\") is not equal to (\"2\")\nTest Suite 'MyAppTests' failed at 2026-03-10 12:00:01\nExecuted 2 tests, with 1 failure in 0.003 seconds"
+
+[[tests.swift-test]]
+name = "compile error before tests"
+input = """
+Compiling MyApp MyApp.swift
+/Users/dev/MyApp/Sources/MyApp/main.swift:5:1: error: use of unresolved identifier 'foo'
+foo()
+^~~
+error: build had 1 command failure
+"""
+expected = "/Users/dev/MyApp/Sources/MyApp/main.swift:5:1: error: use of unresolved identifier 'foo'\nfoo()\n^~~\nerror: build had 1 command failure"

src/filters/swiftformat.toml

@@ -0,0 +1,38 @@
+[filters.swiftformat]
+description = "Compact swiftformat output — show changed files count"
+match_command = "^swiftformat\\b"
+strip_ansi = true
+strip_lines_matching = [
+  "^\\s*$",
+  "^Running SwiftFormat",
+  "^Reading config",
+  "^\\d+/\\d+ files",
+]
+match_output = [
+  { pattern = "0 files would have been changed", message = "ok (swiftformat: no changes needed)" },
+  { pattern = "SwiftFormat completed. 0/", message = "ok (swiftformat: no changes needed)" },
+]
+max_lines = 40
+on_empty = "ok (swiftformat: no output)"
+
+[[tests.swiftformat]]
+name = "no changes needed"
+input = """
+Running SwiftFormat...
+Reading config file at /Users/dev/App/.swiftformat
+0 files would have been changed out of 12 files inspected
+SwiftFormat completed. 0/12 files updated.
+"""
+expected = "ok (swiftformat: no changes needed)"
+
+[[tests.swiftformat]]
+name = "files changed"
+input = """
+Running SwiftFormat...
+Reading config file at /Users/dev/App/.swiftformat
+/Users/dev/App/ViewController.swift
+/Users/dev/App/Model.swift
+2 files would have been changed out of 12 files inspected
+SwiftFormat completed. 2/12 files updated.
+"""
+expected = "/Users/dev/App/ViewController.swift\n/Users/dev/App/Model.swift\n2 files would have been changed out of 12 files inspected\nSwiftFormat completed. 2/12 files updated."

src/filters/swiftlint.toml

@@ -0,0 +1,39 @@
+[filters.swiftlint]
+description = "Compact swiftlint output — strip passing files, show violations grouped"
+match_command = "^swiftlint\\b"
+strip_ansi = true
+strip_lines_matching = [
+  "^\\s*$",
+  "^Linting ",
+  "^Done linting!",
+  "^Loading configuration",
+]
+max_lines = 60
+on_empty = "ok (swiftlint: no violations)"
+
+[[tests.swiftlint]]
+name = "no violations"
+input = """
+Loading configuration from '.swiftlint.yml'
+Linting 'ViewController.swift' (1/5)
+Linting 'AppDelegate.swift' (2/5)
+Linting 'Model.swift' (3/5)
+Linting 'Service.swift' (4/5)
+Linting 'Config.swift' (5/5)
+Done linting! Found 0 violations, 0 serious in 5 files.
+"""
+expected = "ok (swiftlint: no violations)"
+
+[[tests.swiftlint]]
+name = "violations shown"
+input = """
+Loading configuration from '.swiftlint.yml'
+Linting 'ViewController.swift' (1/3)
+Linting 'AppDelegate.swift' (2/3)
+Linting 'Model.swift' (3/3)
+/Users/dev/App/ViewController.swift:42:1: warning: Line Length Violation: Line should be 120 characters or less; currently it has 145 characters (line_length)
+/Users/dev/App/ViewController.swift:58:5: warning: Force Cast Violation: Force casts should be avoided (force_cast)
+/Users/dev/App/Model.swift:12:1: error: Function Body Length Violation: Function body should span 50 lines or less (function_body_length)
+Done linting! Found 3 violations, 1 serious in 3 files.
+"""
+expected = "/Users/dev/App/ViewController.swift:42:1: warning: Line Length Violation: Line should be 120 characters or less; currently it has 145 characters (line_length)\n/Users/dev/App/ViewController.swift:58:5: warning: Force Cast Violation: Force casts should be avoided (force_cast)\n/Users/dev/App/Model.swift:12:1: error: Function Body Length Violation: Function body should span 50 lines or less (function_body_length)\nDone linting! Found 3 violations, 1 serious in 3 files."

src/init.rs

@@ -2356,12 +2356,16 @@ pub fn run_copilot(verbose: u8) -> Result<()> {
     let github_dir = Path::new(".github");
     let hooks_dir = github_dir.join("hooks");
 
-    fs::create_dir_all(&hooks_dir)
-        .context("Failed to create .github/hooks/ directory")?;
+    fs::create_dir_all(&hooks_dir).context("Failed to create .github/hooks/ directory")?;
 
     // 1. Write hook config
     let hook_path = hooks_dir.join("rtk-rewrite.json");
-    write_if_changed(&hook_path, COPILOT_HOOK_JSON, "Copilot hook config", verbose)?;
+    write_if_changed(
+        &hook_path,
+        COPILOT_HOOK_JSON,
+        "Copilot hook config",
+        verbose,
+    )?;
 
     // 2. Write instructions
     let instructions_path = github_dir.join("copilot-instructions.md");

src/rake_cmd.rs

@@ -15,7 +15,7 @@ use anyhow::{Context, Result};
 /// `rails test` which handles single files, multiple files, and line-number
 /// syntax (`file.rb:15`) natively.
 fn select_runner(args: &[String]) -> (&'static str, Vec<String>) {
-    let has_test_subcommand = args.first().map_or(false, |a| a == "test");
+    let has_test_subcommand = args.first().is_some_and(|a| a == "test");
     if !has_test_subcommand {
         return ("rake", args.to_vec());
     }

src/toml_filter.rs

@@ -1610,8 +1610,8 @@ match_command = "^make\\b"
         let filters = make_filters(BUILTIN_TOML);
         assert_eq!(
             filters.len(),
-            58,
-            "Expected exactly 58 built-in filters, got {}. \
+            63,
+            "Expected exactly 63 built-in filters, got {}. \
              Update this count when adding/removing filters in src/filters/.",
             filters.len()
         );
@@ -1668,11 +1668,11 @@ expected = "output line 1\noutput line 2"
         let combined = format!("{}\n\n{}", BUILTIN_TOML, new_filter);
         let filters = make_filters(&combined);
 
-        // All 58 existing filters still present + 1 new = 59
+        // All 63 existing filters still present + 1 new = 64
         assert_eq!(
             filters.len(),
-            59,
-            "Expected 59 filters after concat (58 built-in + 1 new)"
+            64,
+            "Expected 64 filters after concat (63 built-in + 1 new)"
         );
 
         // New filter is discoverable