Simple crash_tests for yaml_edit

pkgs/yaml_edit/test/crash_test/crash_test.dart

@@ -0,0 +1,186 @@
+// Copyright (c) 2025, the Dart project authors. Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+@TestOn('vm')
+library;
+
+import 'dart:io';
+import 'dart:isolate';
+
+import 'package:test/test.dart';
+import 'package:yaml/yaml.dart';
+import 'package:yaml_edit/yaml_edit.dart';
+
+final _scalarStyles = [
+  ScalarStyle.ANY,
+  ScalarStyle.PLAIN,
+  ScalarStyle.LITERAL,
+  ScalarStyle.FOLDED,
+  ScalarStyle.SINGLE_QUOTED,
+  ScalarStyle.DOUBLE_QUOTED,
+];
+
+/// Files with tests that are broken, so we have to skip them
+final _skippedFiles = [
+  'block_strings.yaml',
+  'complex.yaml',
+  'explicit_key_value.yaml',
+  'mangled_json.yaml',
+  'simple_comments.yaml',
+];
+
+/// The crash tests will attempt to enumerate all JSON paths in each input
+/// document and then proceed to make arbitrary mutations trying to see if
+/// [YamlEditor] will crash. Arbitrary mutations include:
+///  - Remove each JSON path
+///  - Prepend and append to each list and map.
+///  - Set each string to 'hello world'
+///  - Set all numbers to 42
+///
+/// Input documents are loaded from: test/crash_test/testdata/*.yaml
+Future<void> main() async {
+  final packageUri = await Isolate.resolvePackageUri(
+      Uri.parse('package:yaml_edit/yaml_edit.dart'));
+
+  final testdataUri = packageUri!.resolve('../test/crash_test/testdata/');
+  final testFiles = Directory.fromUri(testdataUri)
+      .listSync()
+      .whereType<File>()
+      .where((f) => f.path.endsWith('.yaml'))
+      .toList();
+
+  for (final f in testFiles) {
+    final fileName = f.uri.pathSegments.last;
+    final input = f.readAsStringSync();
+    final root = YamlEditor(input);
+
+    test('$fileName is valid YAML', () {
+      loadYamlNode(input);
+    });
+
+    if (_skippedFiles.contains(fileName)) {
+      test(
+        'crash_test.dart for $fileName',
+        () {},
+        skip: 'Known failures in "$fileName"',
+      );
+      continue;
+    }
+
+    for (final (path, node) in _allJsonPaths(root.parseAt([]))) {
+      _testJsonPath(fileName, input, path, node);
+    }
+  }
+}
+
+void _testJsonPath(
+  String fileName,
+  String input,
+  Iterable<Object?> path,
+  YamlNode node,
+) {
+  final editorName = 'YamlEditor($fileName)';
+
+  // Try to remove the node
+  test('$editorName.remove($path)', () {
+    final editor = YamlEditor(input);
+    editor.remove(path);
+  });
+
+  // Try to update path to a string
+  test('$editorName.update($path, \'updated string\')', () {
+    final editor = YamlEditor(input);
+    editor.update(path, 'updated string');
+  });
+
+  // Try to update path to an integer
+  test('$editorName.update($path, 42)', () {
+    final editor = YamlEditor(input);
+    editor.update(path, 42);
+  });
+
+  // Try to set a multi-line string for each style
+  for (final style in _scalarStyles) {
+    test('$editorName.update($path, \'foo\\nbar\') as $style', () {
+      final editor = YamlEditor(input);
+      editor.update(path, YamlScalar.wrap('foo\nbar', style: style));
+    });
+  }
+
+  // If it's a list, we try to insert into the list for each index
+  if (node is YamlList) {
+    for (var i = 0; i < node.length + 1; i++) {
+      test('$editorName.insertIntoList($path, $i, 42)', () {
+        final editor = YamlEditor(input);
+        editor.insertIntoList(path, i, 42);
+      });
+
+      test('$editorName.insertIntoList($path, $i, \'new string\')', () {
+        final editor = YamlEditor(input);
+        editor.insertIntoList(path, i, 'new string');
+      });
+
+      for (final style in _scalarStyles) {
+        test('$editorName.insertIntoList($path, $i, \'foo\\nbar\') as $style',
+            () {
+          final editor = YamlEditor(input);
+          editor.insertIntoList(
+              path,
+              i,
+              YamlScalar.wrap(
+                'foo\nbar',
+                style: style,
+              ));
+        });
+      }
+    }
+  }
+
+  // If it's a map, we try to insert a new key (if the new-key name isn't used)
+  if (node is YamlMap && !node.containsKey('new-key')) {
+    final newPath = [...path, 'new-key'];
+
+    test('$editorName.update($newPath, 42)', () {
+      final editor = YamlEditor(input);
+      editor.update(newPath, 42);
+    });
+
+    test('$editorName.update($newPath, \'new string\')', () {
+      final editor = YamlEditor(input);
+      editor.update(newPath, 'new string');
+    });
+
+    for (final style in _scalarStyles) {
+      test('$editorName.update($newPath, \'foo\\nbar\') as $style', () {
+        final editor = YamlEditor(input);
+        editor.update(
+            newPath,
+            YamlScalar.wrap(
+              'foo\nbar',
+              style: style,
+            ));
+      });
+    }
+  }
+}
+
+Iterable<(Iterable<Object?>, YamlNode)> _allJsonPaths(
+  YamlNode node, [
+  Iterable<Object?> parents = const [],
+]) sync* {
+  yield (parents, node);
+
+  if (node is YamlMap) {
+    for (final entry in node.nodes.entries) {
+      final key = entry.key as YamlNode;
+      final value = entry.value;
+      yield* _allJsonPaths(value, [...parents, key.value]);
+    }
+  } else if (node is YamlList) {
+    for (var i = 0; i < node.nodes.length; i++) {
+      final value = node.nodes[i];
+      yield* _allJsonPaths(value, [...parents, i]);
+    }
+  }
+}

pkgs/yaml_edit/test/crash_test/testdata/block_strings.yaml

@@ -0,0 +1,41 @@
+block-strings:     # annoying comment (maybe)
+ - folded:
+    - clip: >
+        first line
+
+        skipped line
+
+
+# This is a comment
+  # this too!
+       # And this one
+    - strip: >+  # We can have comments here
+        first line
+
+        skipped line
+
+
+    - keep:  >-
+        first line
+
+        skipped line
+       # comment why not!
+             # and again
+ - literal:
+    - clip: |
+        first line
+
+        skipped line
+
+
+    - strip: |+
+        first line
+
+        skipped line
+
+
+    - keep:  |-
+        first line
+
+        skipped line
+

pkgs/yaml_edit/test/crash_test/testdata/complex.yaml

@@ -0,0 +1,93 @@
+  # Start comment
+? string
+     # why not here too!
+: hello world
+# top-level comment
+   # comment again
+? block-strings     # annoying comment (maybe)
+: - folded:
+    - clip: >
+        first line
+
+        skipped line
+
+
+# This is a comment
+  # this too!
+       # And this one
+    - strip: >+  # We can have comments here
+        first line
+
+        skipped line
+
+
+    - keep:  >-
+        first line
+
+        skipped line
+       # comment why not!
+             # and again
+  - literal:
+    - clip: |
+        first line
+
+        skipped line
+
+
+    - strip: |+
+        first line
+
+        skipped line
+
+
+    - keep:  |-
+        first line
+
+        skipped line
+
+
+? key
+: value # Note: this works
+          # This too ?
+? map
+: k1: 1
+  k2: 2
+  k3: 3
+? list
+: - 1
+  - 2
+  - 3
+? inlineMap
+: {k1: 1, k2: 2, k3: 3}
+? inlineList
+: [1, 2, 3]
+? complex-object
+:   foo: 42
+    bar:
+     - 'test test'
+     - |
+         hello world
+     - "test string"
+     - {
+    a: 1,
+    b:
+   'hello world'
+  }
+? json-with-comments
+: {
+  "key": "value",
+  'string with newline': 'hello
+  world'
+  , 32      : 42
+,   list :
+[ # We can make multi-line strings inline!
+  'foo
+
+
+bar' # comment before comma
+,  -32.4
+   # Comment again.
+, # Comment on the comma!
+# trailing comma, why not
+]
+}

pkgs/yaml_edit/test/crash_test/testdata/explicit_key_value.yaml

@@ -0,0 +1,12 @@
+? map
+: k1: 1
+  k2: 2
+  k3: 3
+? list
+: - 1
+  - 2
+  - 3
+? inlineMap
+: {k1: 1, k2: 2, k3: 3}
+? inlineList
+: [1, 2, 3]

pkgs/yaml_edit/test/crash_test/testdata/json.yaml

@@ -0,0 +1,12 @@
+{
+  "string": "hello world",
+  "map": {
+    "foo": 42,
+    "bar": "baz"
+  },
+  "list": [
+    1,
+    2,
+    3
+  ]
+}

pkgs/yaml_edit/test/crash_test/testdata/json_comments.yaml

@@ -0,0 +1,15 @@
+# Initial comment
+{
+  "string": "hello world", # Great message
+  "map": {
+    "foo": 42, # Fantastic number
+    "bar": "baz"
+  },
+  "list": [
+    1, # This is a good list
+    2, # This comment is good
+        # But this?
+          # Or this?
+    3
+  ]
+}

pkgs/yaml_edit/test/crash_test/testdata/mangled_json.yaml

@@ -0,0 +1,15 @@
+{
+  "string":
+"hello world",
+  "map": {
+    "foo":
+42
+,"bar":
+         "baz"
+  }
+    ,"list": [
+1,2
+,
+    3
+,]
+}

pkgs/yaml_edit/test/crash_test/testdata/simple.yaml

@@ -0,0 +1,8 @@
+string: 'hello world'
+map:
+ foo: 42
+ bar: 'baz'
+list:
+ - 1
+ - 2
+ - 3

pkgs/yaml_edit/test/crash_test/testdata/simple_comments.yaml

@@ -0,0 +1,9 @@
+# Initial comment
+string: 'hello world' # Comment
+map:
+ foo: 42 # Best number
+ bar: 'baz'
+list: # Great starter list
+ - 1
+ - 2
+ - 3