Declare locals final where possible (#255)

This makes it easier to reason about the code. Enables the prefer_final_locals lint.
dart-lang · May 14, 2019 · 3453196 · 3453196
1 parent 4add8bd
commit 3453196
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Showing 17 changed files with 188 additions and 189 deletions.
diff --git a/analysis_options.yaml b/analysis_options.yaml
@@ -63,7 +63,7 @@ linter:
     - package_api_docs
     - package_prefixed_library_names
     - prefer_equal_for_default_values
-    # - prefer_final_locals
+    - prefer_final_locals
     - prefer_generic_function_type_aliases
     - prefer_is_not_empty
     # - public_member_api_docs

diff --git a/bin/collect_coverage.dart b/bin/collect_coverage.dart
@@ -17,9 +17,9 @@ Future<Null> main(List<String> arguments) async {
     print('${rec.level.name}: ${rec.time}: ${rec.message}');
   });
 
-  var options = _parseArgs(arguments);
+  final options = _parseArgs(arguments);
   await Chain.capture(() async {
-    var coverage = await collect(
+    final coverage = await collect(
         options.serviceUri, options.resume, options.waitPaused,
         timeout: options.timeout);
     options.out.write(json.encode(coverage));
@@ -45,7 +45,7 @@ class Options {
 }
 
 Options _parseArgs(List<String> arguments) {
-  var parser = ArgParser()
+  final parser = ArgParser()
     ..addOption('host',
         abbr: 'H',
         help: 'remote VM host. DEPRECATED: use --uri',
@@ -67,7 +67,7 @@ Options _parseArgs(List<String> arguments) {
         abbr: 'r', defaultsTo: false, help: 'resume all isolates on exit')
     ..addFlag('help', abbr: 'h', negatable: false, help: 'show this help');
 
-  var args = parser.parse(arguments);
+  final args = parser.parse(arguments);
 
   void printUsage() {
     print('Usage: dart collect_coverage.dart --uri=http://... [OPTION...]\n');
@@ -102,10 +102,10 @@ Options _parseArgs(List<String> arguments) {
   if (args['out'] == 'stdout') {
     out = stdout;
   } else {
-    var outfile = File(args['out'])..createSync(recursive: true);
+    final outfile = File(args['out'])..createSync(recursive: true);
     out = outfile.openWrite();
   }
-  var timeout = (args['connect-timeout'] == null)
+  final timeout = (args['connect-timeout'] == null)
       ? null
       : Duration(seconds: int.parse(args['connect-timeout']));
   return Options(

diff --git a/bin/format_coverage.dart b/bin/format_coverage.dart
@@ -30,7 +30,7 @@ class Environment {
 Future<Null> main(List<String> arguments) async {
   final env = parseArgs(arguments);
 
-  List<File> files = filesToProcess(env.input);
+  final List<File> files = filesToProcess(env.input);
   if (env.verbose) {
     print('Environment:');
     print('  # files: ${files.length}');
@@ -41,22 +41,22 @@ Future<Null> main(List<String> arguments) async {
     print('  report-on: ${env.reportOn}');
   }
 
-  var clock = Stopwatch()..start();
-  var hitmap = await parseCoverage(files, env.workers);
+  final clock = Stopwatch()..start();
+  final hitmap = await parseCoverage(files, env.workers);
 
   // All workers are done. Process the data.
   if (env.verbose) {
     print('Done creating global hitmap. Took ${clock.elapsedMilliseconds} ms.');
   }
 
   String output;
-  var resolver = env.bazel
+  final resolver = env.bazel
       ? BazelResolver(workspacePath: env.bazelWorkspace)
       : Resolver(
           packagesPath: env.packagesPath,
           packageRoot: env.pkgRoot,
           sdkRoot: env.sdkRoot);
-  var loader = Loader();
+  final loader = Loader();
   if (env.prettyPrint) {
     output =
         await PrettyPrintFormatter(resolver, loader, reportOn: env.reportOn)
@@ -95,7 +95,7 @@ Future<Null> main(List<String> arguments) async {
 /// processing.
 Environment parseArgs(List<String> arguments) {
   final env = Environment();
-  var parser = ArgParser();
+  final parser = ArgParser();
 
   parser.addOption('sdk-root', abbr: 's', help: 'path to the SDK root');
   parser.addOption('package-root', abbr: 'p', help: 'path to the package root');
@@ -126,7 +126,7 @@ Environment parseArgs(List<String> arguments) {
       abbr: 'v', negatable: false, help: 'verbose output');
   parser.addFlag('help', abbr: 'h', negatable: false, help: 'show this help');
 
-  var args = parser.parse(arguments);
+  final args = parser.parse(arguments);
 
   void printUsage() {
     print('Usage: dart format_coverage.dart [OPTION...]\n');
@@ -182,8 +182,8 @@ Environment parseArgs(List<String> arguments) {
   if (args['out'] == 'stdout') {
     env.output = stdout;
   } else {
-    var outpath = p.absolute(p.normalize(args['out']));
-    var outfile = File(outpath)..createSync(recursive: true);
+    final outpath = p.absolute(p.normalize(args['out']));
+    final outfile = File(outpath)..createSync(recursive: true);
     env.output = outfile.openWrite();
   }
 
@@ -220,7 +220,7 @@ Environment parseArgs(List<String> arguments) {
 /// are contained by it if it is a directory, or a [List] containing the file if
 /// it is a file.
 List<File> filesToProcess(String absPath) {
-  var filePattern = RegExp(r'^dart-cov-\d+-\d+.json$');
+  final filePattern = RegExp(r'^dart-cov-\d+-\d+.json$');
   if (FileSystemEntity.isDirectorySync(absPath)) {
     return Directory(absPath)
         .listSync(recursive: true)

diff --git a/bin/run_and_collect.dart b/bin/run_and_collect.dart
@@ -7,6 +7,6 @@ import 'dart:async';
 import 'package:coverage/src/run_and_collect.dart';
 
 Future<Null> main(List<String> args) async {
-  Map results = await runAndCollect(args[0], packageRoot: args[1]);
+  final Map results = await runAndCollect(args[0], packageRoot: args[1]);
   print(results);
 }
diff --git a/lib/src/collect.dart b/lib/src/collect.dart
@@ -29,9 +29,9 @@ Future<Map<String, dynamic>> collect(
   if (serviceUri == null) throw ArgumentError('serviceUri must not be null');
 
   // Create websocket URI. Handle any trailing slashes.
-  var pathSegments = serviceUri.pathSegments.where((c) => c.isNotEmpty).toList()
-    ..add('ws');
-  var uri = serviceUri.replace(scheme: 'ws', pathSegments: pathSegments);
+  final pathSegments =
+      serviceUri.pathSegments.where((c) => c.isNotEmpty).toList()..add('ws');
+  final uri = serviceUri.replace(scheme: 'ws', pathSegments: pathSegments);
 
   VMServiceClient vmService;
   await retry(() async {
@@ -58,22 +58,22 @@ Future<Map<String, dynamic>> collect(
 }
 
 Future<Map<String, dynamic>> _getAllCoverage(VMServiceClient service) async {
-  var vm = await service.getVM();
-  var allCoverage = <Map<String, dynamic>>[];
+  final vm = await service.getVM();
+  final allCoverage = <Map<String, dynamic>>[];
 
   for (var isolateRef in vm.isolates) {
-    var isolate = await isolateRef.load();
-    var report = await isolate.getSourceReport(forceCompile: true);
-    var coverage = await _getCoverageJson(service, report);
+    final isolate = await isolateRef.load();
+    final report = await isolate.getSourceReport(forceCompile: true);
+    final coverage = await _getCoverageJson(service, report);
     allCoverage.addAll(coverage);
   }
   return <String, dynamic>{'type': 'CodeCoverage', 'coverage': allCoverage};
 }
 
 Future _resumeIsolates(VMServiceClient service) async {
-  var vm = await service.getVM();
+  final vm = await service.getVM();
   for (var isolateRef in vm.isolates) {
-    var isolate = await isolateRef.load();
+    final isolate = await isolateRef.load();
     if (isolate.isPaused) {
       await isolateRef.resume();
     }
@@ -82,9 +82,9 @@ Future _resumeIsolates(VMServiceClient service) async {
 
 Future _waitIsolatesPaused(VMServiceClient service, {Duration timeout}) async {
   Future allPaused() async {
-    var vm = await service.getVM();
+    final vm = await service.getVM();
     for (var isolateRef in vm.isolates) {
-      var isolate = await isolateRef.load();
+      final isolate = await isolateRef.load();
       if (!isolate.isPaused) throw "Unpaused isolates remaining.";
     }
   }
@@ -95,33 +95,33 @@ Future _waitIsolatesPaused(VMServiceClient service, {Duration timeout}) async {
 /// Returns a JSON coverage list backward-compatible with pre-1.16.0 SDKs.
 Future<List<Map<String, dynamic>>> _getCoverageJson(
     VMServiceClient service, VMSourceReport report) async {
-  var scriptRefs = report.ranges.map((r) => r.script).toSet();
-  var scripts = <VMScriptRef, VMScript>{};
+  final scriptRefs = report.ranges.map((r) => r.script).toSet();
+  final scripts = <VMScriptRef, VMScript>{};
   for (var ref in scriptRefs) {
     scripts[ref] = await ref.load();
   }
 
   // script uri -> { line -> hit count }
-  var hitMaps = <Uri, Map<int, int>>{};
+  final hitMaps = <Uri, Map<int, int>>{};
   for (var range in report.ranges) {
     // Not returned in scripts section of source report.
     if (range.script.uri.scheme == 'evaluate') continue;
 
     hitMaps.putIfAbsent(range.script.uri, () => <int, int>{});
-    var hitMap = hitMaps[range.script.uri];
-    var script = scripts[range.script];
+    final hitMap = hitMaps[range.script.uri];
+    final script = scripts[range.script];
     for (VMScriptToken hit in range.hits ?? []) {
-      var line = script.sourceLocation(hit).line + 1;
+      final line = script.sourceLocation(hit).line + 1;
       hitMap[line] = hitMap.containsKey(line) ? hitMap[line] + 1 : 1;
     }
     for (VMScriptToken miss in range.misses ?? []) {
-      var line = script.sourceLocation(miss).line + 1;
+      final line = script.sourceLocation(miss).line + 1;
       hitMap.putIfAbsent(line, () => 0);
     }
   }
 
   // Output JSON
-  var coverage = <Map<String, dynamic>>[];
+  final coverage = <Map<String, dynamic>>[];
   hitMaps.forEach((uri, hitMap) {
     coverage.add(_toScriptCoverageJson(uri, hitMap));
   });
@@ -131,8 +131,8 @@ Future<List<Map<String, dynamic>>> _getCoverageJson(
 /// Returns a JSON hit map backward-compatible with pre-1.16.0 SDKs.
 Map<String, dynamic> _toScriptCoverageJson(
     Uri scriptUri, Map<int, int> hitMap) {
-  var json = <String, dynamic>{};
-  var hits = <int>[];
+  final json = <String, dynamic>{};
+  final hits = <int>[];
   hitMap.forEach((line, hitCount) {
     hits.add(line);
     hits.add(hitCount);

diff --git a/lib/src/formatter.dart b/lib/src/formatter.dart
@@ -32,10 +32,10 @@ class LcovFormatter implements Formatter {
 
   @override
   Future<String> format(Map hitmap) async {
-    _PathFilter pathFilter = _getPathFilter(reportOn);
-    var buf = StringBuffer();
+    final _PathFilter pathFilter = _getPathFilter(reportOn);
+    final buf = StringBuffer();
     for (var key in hitmap.keys) {
-      Map<int, int> v = hitmap[key];
+      final Map<int, int> v = hitmap[key];
       var source = resolver.resolve(key);
       if (source == null) {
         continue;
@@ -81,11 +81,11 @@ class PrettyPrintFormatter implements Formatter {
 
   @override
   Future<String> format(Map hitmap) async {
-    _PathFilter pathFilter = _getPathFilter(reportOn);
-    var buf = StringBuffer();
+    final _PathFilter pathFilter = _getPathFilter(reportOn);
+    final buf = StringBuffer();
     for (var key in hitmap.keys) {
-      Map<int, int> v = hitmap[key];
-      var source = resolver.resolve(key);
+      final Map<int, int> v = hitmap[key];
+      final source = resolver.resolve(key);
       if (source == null) {
         continue;
       }
@@ -94,7 +94,7 @@ class PrettyPrintFormatter implements Formatter {
         continue;
       }
 
-      var lines = await loader.load(source);
+      final lines = await loader.load(source);
       if (lines == null) {
         continue;
       }
@@ -119,6 +119,6 @@ typedef _PathFilter = bool Function(String path);
 _PathFilter _getPathFilter(List<String> reportOn) {
   if (reportOn == null) return (String path) => true;
 
-  var absolutePaths = reportOn.map(p.absolute).toList();
+  final absolutePaths = reportOn.map(p.absolute).toList();
   return (String path) => absolutePaths.any((item) => path.startsWith(item));
 }
diff --git a/lib/src/hitmap.dart b/lib/src/hitmap.dart
@@ -12,37 +12,37 @@ import 'dart:io';
 /// `jsonResult` is expected to be a List<Map<String, dynamic>>.
 Map<String, Map<int, int>> createHitmap(List jsonResult) {
   // Map of source file to map of line to hit count for that line.
-  var globalHitMap = <String, Map<int, int>>{};
+  final globalHitMap = <String, Map<int, int>>{};
 
   void addToMap(Map<int, int> map, int line, int count) {
-    var oldCount = map.putIfAbsent(line, () => 0);
+    final oldCount = map.putIfAbsent(line, () => 0);
     map[line] = count + oldCount;
   }
 
   for (Map<String, dynamic> e in jsonResult) {
-    String source = e['source'];
+    final String source = e['source'];
     if (source == null) {
       // Couldn't resolve import, so skip this entry.
       continue;
     }
 
-    var sourceHitMap = globalHitMap.putIfAbsent(source, () => <int, int>{});
-    List<dynamic> hits = e['hits'];
+    final sourceHitMap = globalHitMap.putIfAbsent(source, () => <int, int>{});
+    final List<dynamic> hits = e['hits'];
     // hits is a flat array of the following format:
     // [ <line|linerange>, <hitcount>,...]
     // line: number.
     // linerange: '<line>-<line>'.
     for (var i = 0; i < hits.length; i += 2) {
-      dynamic k = hits[i];
+      final dynamic k = hits[i];
       if (k is num) {
         // Single line.
         addToMap(sourceHitMap, k, hits[i + 1]);
       } else {
         assert(k is String);
         // Linerange. We expand line ranges to actual lines at this point.
-        int splitPos = k.indexOf('-');
-        int start = int.parse(k.substring(0, splitPos));
-        int end = int.parse(k.substring(splitPos + 1));
+        final int splitPos = k.indexOf('-');
+        final start = int.parse(k.substring(0, splitPos));
+        final end = int.parse(k.substring(splitPos + 1));
         for (var j = start; j <= end; j++) {
           addToMap(sourceHitMap, j, hits[i + 1]);
         }
@@ -72,10 +72,10 @@ void mergeHitmaps(
 
 /// Generates a merged hitmap from a set of coverage JSON files.
 Future<Map> parseCoverage(Iterable<File> files, int _) async {
-  var globalHitmap = <String, Map<int, int>>{};
+  final globalHitmap = <String, Map<int, int>>{};
   for (var file in files) {
-    String contents = file.readAsStringSync();
-    List jsonResult = json.decode(contents)['coverage'];
+    final contents = file.readAsStringSync();
+    final List jsonResult = json.decode(contents)['coverage'];
     mergeHitmaps(createHitmap(jsonResult), globalHitmap);
   }
   return globalHitmap;