small housekeeping

- add github actions to run linter and test for PR
- update analysis_options.yaml more pedantic
- address linter warning
-

.github/workflows/test.yaml

@@ -0,0 +1,21 @@
+name: test
+on:
+  pull_request:
+    types: [opened, synchronize]
+  push:
+    branches: [ master, main ]
+jobs:
+  test:
+    name: test
+    runs-on: ubuntu-latest
+    container:
+      image:  google/dart:latest
+    steps:
+      - name: set up repository
+        uses: actions/checkout@v2
+      - name: install deps
+        run: pub get
+      - name: analyzer
+        run: dartanalyzer --fatal-warnings --fatal-infos .
+      - name: test
+        run: dart test

analysis_options.yaml

@@ -2,4 +2,21 @@ linter:
   rules:
     unawaited_futures: true
     curly_braces_in_flow_control_structures: true
-    avoid_catches_without_on_clauses: true
+    avoid_catches_without_on_clauses: true
+    avoid_empty_else: true
+    avoid_print: true
+    empty_catches: true
+    prefer_const_constructors_in_immutables: true
+    prefer_const_constructors: true
+    prefer_const_declarations: true
+    unnecessary_const: true
+    prefer_final_fields: true
+    prefer_null_aware_operators: true
+    provide_deprecation_message: true
+    unnecessary_new: true
+    unnecessary_null_aware_assignments: true
+    unnecessary_null_in_if_null_operators: true
+    unnecessary_overrides: true
+    unnecessary_parenthesis: true
+    unnecessary_statements: true
+    valid_regexps: true

test/parser_test.dart

@@ -312,7 +312,9 @@ void main() {
         fail('Did not throw.');
       } on Exception catch (ex, st) {
         if (ex is! TemplateException) {
+          // ignore: avoid_print
           print(ex);
+          // ignore: avoid_print
           print(st);
         }
         return ex;
@@ -381,28 +383,25 @@ bool nodeEqual(a, b) {
         a.start == b.start &&
         a.end == b.end;
   } else if (a is VariableNode) {
-    return a is VariableNode &&
-        a.name == b.name &&
+    return a.name == b.name &&
         a.escape == b.escape &&
         a.start == b.start &&
         a.end == b.end;
   } else if (a is SectionNode) {
-    return a is SectionNode &&
-        a.name == b.name &&
+    return a.name == b.name &&
         a.delimiters == b.delimiters &&
         a.inverse == b.inverse &&
         a.start == b.start &&
         a.end == b.end;
   } else if (a is PartialNode) {
-    return a is PartialNode && a.name == b.name && a.indent == b.indent;
+    return a.name == b.name && a.indent == b.indent;
   } else {
     return false;
   }
 }
 
 bool tokenEqual(Token a, Token b) {
-  return a is Token &&
-      a.type == b.type &&
+  return a.type == b.type &&
       a.value == b.value &&
       a.start == b.start &&
       a.end == b.end;