Commit 8f07a586 authored by Jacob Richman's avatar Jacob Richman Committed by GitHub

Add hasAGoodToStringDeep and equalsIgnoringHashCodes methods. (#10935)

* Add hasAGoodToStringDeep and equalsIgnoringHashCodes methods.

Methods simplify testing of toStringDeep calls and other cases where
methods return strings containing hash codes.
parent f4f81e9a
......@@ -117,6 +117,23 @@ const Matcher isNotInCard = const _IsNotInCard();
/// empty, and does not contain the default `Instance of ...` string.
const Matcher hasOneLineDescription = const _HasOneLineDescription();
/// Asserts that an object's toStringDeep() is a plausible multi-line
/// description.
///
/// Specifically, this matcher checks that an object's
/// `toStringDeep(prefixLineOne, prefixOtherLines)`:
///
/// * Does not have leading or trailing whitespace.
/// * Does not contain the default `Instance of ...` string.
/// * The last line has characters other than tree connector characters and
/// whitespace. For example: the line ` │ ║ ╎` has only tree connector
/// characters and whitespace.
/// * Does not contain lines with trailing white space.
/// * Has multiple lines.
/// * The first line starts with `prefixLineOne`
/// * All subsequent lines start with `prefixOtherLines`.
const Matcher hasAGoodToStringDeep = const _HasGoodToStringDeep();
/// A matcher for functions that throw [FlutterError].
///
/// This is equivalent to `throwsA(const isInstanceOf<FlutterError>())`.
......@@ -179,6 +196,23 @@ Matcher moreOrLessEquals(double value, { double epsilon: 1e-10 }) {
return new _MoreOrLessEquals(value, epsilon);
}
/// Asserts that two [String]s are equal after normalizing likely hash codes.
///
/// A `#` followed by 5 hexadecimal digits is assumed to be a short hash code
/// and is normalized to #00000.
///
/// See Also:
///
/// * [describeIdentity], a method that generates short descriptions of objects
/// with ids that match the pattern #[0-9a-f]{5}.
/// * [shortHash], a method that generates a 5 character long hexadecimal
/// [String] based on [Object.hashCode].
/// * [TreeDiagnosticsMixin.toStringDeep], a method that returns a [String]
/// typically containing multiple hash codes.
Matcher equalsIgnoringHashCodes(String value) {
return new _EqualsIgnoringHashCodes(value);
}
class _FindsWidgetMatcher extends Matcher {
const _FindsWidgetMatcher(this.min, this.max);
......@@ -352,6 +386,185 @@ class _HasOneLineDescription extends Matcher {
Description describe(Description description) => description.add('one line description');
}
class _EqualsIgnoringHashCodes extends Matcher {
_EqualsIgnoringHashCodes(String v) : _value = _normalize(v);
final String _value;
static final Object _mismatchedValueKey = new Object();
static String _normalize(String s) {
return s.replaceAll(new RegExp(r'#[0-9a-f]{5}'), '#00000');
}
@override
bool matches(dynamic object, Map<dynamic, dynamic> matchState) {
final String description = _normalize(object);
if (_value != description) {
matchState[_mismatchedValueKey] = description;
return false;
}
return true;
}
@override
Description describe(Description description) {
return description.add('multi line description equals $_value');
}
@override
Description describeMismatch(
dynamic item,
Description mismatchDescription,
Map<dynamic, dynamic> matchState,
bool verbose
) {
if (matchState.containsKey(_mismatchedValueKey)) {
final String actualValue = matchState[_mismatchedValueKey];
// Leading whitespace is added so that lines in the multi-line
// description returned by addDescriptionOf are all indented equally
// which makes the output easier to read for this case.
return mismatchDescription
.add('expected normalized value\n ')
.addDescriptionOf(_value)
.add('\nbut got\n ')
.addDescriptionOf(actualValue);
}
return mismatchDescription;
}
}
/// Returns `true` if [c] represents a whitespace code unit.
bool _isWhitespace(int c) => (c <= 0x000D && c >= 0x0009) || c == 0x0020;
/// Returns `true` if [c] represents a vertical line unicode line art code unit.
///
/// See [https://en.wikipedia.org/wiki/Box-drawing_character]. This method only
/// specifies vertical line art code units currently used by Flutter line art.
/// There are other line art characters that technically also represent vertical
/// lines.
bool _isVerticalLine(int c) {
return c == 0x2502 || c == 0x2503 || c == 0x2551 || c == 0x254e;
}
/// Returns whether a [line] is all vertical tree connector characters.
///
/// Example vertical tree connector characters: `│ ║ ╎`.
/// The last line of a text tree contains only vertical tree connector
/// characters indicates a poorly formatted tree.
bool _isAllTreeConnectorCharacters(String line) {
for (int i = 0; i < line.length; ++i) {
final int c = line.codeUnitAt(i);
if (!_isWhitespace(c) && !_isVerticalLine(c))
return false;
}
return true;
}
class _HasGoodToStringDeep extends Matcher {
const _HasGoodToStringDeep();
static final Object _toStringDeepErrorDescriptionKey = new Object();
@override
bool matches(dynamic object, Map<dynamic, dynamic> matchState) {
final List<String> issues = <String>[];
String description = object.toStringDeep();
if (description.endsWith('\n')) {
// Trim off trailing \n as the remaining calculations assume
// the description does not end with a trailing \n.
description = description.substring(0, description.length - 1);
} else {
issues.add('Not terminated with a line break.');
}
if (description.trim() != description)
issues.add('Has trailing whitespace.');
final List<String> lines = description.split('\n');
if (lines.length < 2)
issues.add('Does not have multiple lines.');
if (description.contains('Instance of '))
issues.add('Contains text "Instance of ".');
for (int i = 0; i < lines.length; ++i) {
final String line = lines[i];
if (line.isEmpty)
issues.add('Line ${i+1} is empty.');
if (line.trimRight() != line)
issues.add('Line ${i+1} has trailing whitespace.');
}
if (_isAllTreeConnectorCharacters(lines.last))
issues.add('Last line is all tree connector characters.');
// If a toStringDeep method doesn't properly handle nested values that
// contain line breaks it can fail to add the required prefixes to all
// lined when toStringDeep is called specifying prefixes.
final String prefixLineOne = 'PREFIX_LINE_ONE____';
final String prefixOtherLines = 'PREFIX_OTHER_LINES_';
final List<String> prefixIssues = <String>[];
String descriptionWithPrefixes =
object.toStringDeep(prefixLineOne, prefixOtherLines);
if (descriptionWithPrefixes.endsWith('\n')) {
// Trim off trailing \n as the remaining calculations assume
// the description does not end with a trailing \n.
descriptionWithPrefixes = descriptionWithPrefixes.substring(
0, descriptionWithPrefixes.length - 1);
}
final List<String> linesWithPrefixes = descriptionWithPrefixes.split('\n');
if (!linesWithPrefixes.first.startsWith(prefixLineOne))
prefixIssues.add('First line does not contain expected prefix.');
for (int i = 1; i < linesWithPrefixes.length; ++i) {
if (!linesWithPrefixes[i].startsWith(prefixOtherLines))
prefixIssues.add('Line ${i+1} does not contain the expected prefix.');
}
final StringBuffer errorDescription = new StringBuffer();
if (issues.isNotEmpty) {
errorDescription.writeln('Bad toStringDeep():');
errorDescription.writeln(description);
errorDescription.writeAll(issues, '\n');
}
if (prefixIssues.isNotEmpty) {
errorDescription.writeln(
'Bad toStringDeep("$prefixLineOne", "$prefixOtherLines"):');
errorDescription.writeln(descriptionWithPrefixes);
errorDescription.writeAll(prefixIssues, '\n');
}
if (errorDescription.isNotEmpty) {
matchState[_toStringDeepErrorDescriptionKey] =
errorDescription.toString();
return false;
}
return true;
}
@override
Description describeMismatch(
dynamic item,
Description mismatchDescription,
Map<dynamic, dynamic> matchState,
bool verbose
) {
if (matchState.containsKey(_toStringDeepErrorDescriptionKey)) {
return mismatchDescription.add(
matchState[_toStringDeepErrorDescriptionKey]);
}
return mismatchDescription;
}
@override
Description describe(Description description) {
return description.add('multi line description');
}
}
class _MoreOrLessEquals extends Matcher {
const _MoreOrLessEquals(this.value, this.epsilon);
......
......@@ -4,6 +4,43 @@
import 'package:flutter_test/flutter_test.dart';
/// Class that makes it easy to mock common toStringDeep behavior.
class _MockToStringDeep {
_MockToStringDeep(String str) {
final List<String> lines = str.split('\n');
_lines = <String>[];
for (int i = 0; i < lines.length - 1; ++i)
_lines.add('${lines[i]}\n');
// If the last line is empty, that really just means that the previous
// line was terminated with a line break.
if (lines.isNotEmpty && lines.last.isNotEmpty) {
_lines.add(lines.last);
}
}
_MockToStringDeep.fromLines(this._lines);
/// Lines in the message to display when [toStringDeep] is called.
/// For correct toStringDeep behavior, each line should be terminated with a
/// line break.
List<String> _lines;
String toStringDeep([String prefixLineOne="", String prefixOtherLines=""]) {
final StringBuffer sb = new StringBuffer();
if (_lines.isNotEmpty)
sb.write('$prefixLineOne${_lines.first}');
for (int i = 1; i < _lines.length; ++i)
sb.write('$prefixOtherLines${_lines[i]}');
return sb.toString();
}
@override
String toString() => toStringDeep();
}
void main() {
test('hasOneLineDescription', () {
expect('Hello', hasOneLineDescription);
......@@ -13,6 +50,113 @@ void main() {
expect(new Object(), isNot(hasOneLineDescription));
});
test('hasAGoodToStringDeep', () {
expect(new _MockToStringDeep('Hello\n World\n'), hasAGoodToStringDeep);
// Not terminated with a line break.
expect(new _MockToStringDeep('Hello\n World'), isNot(hasAGoodToStringDeep));
// Trailing whitespace on last line.
expect(new _MockToStringDeep('Hello\n World \n'),
isNot(hasAGoodToStringDeep));
expect(new _MockToStringDeep('Hello\n World\t\n'),
isNot(hasAGoodToStringDeep));
// Leading whitespace on line 1.
expect(new _MockToStringDeep(' Hello\n World \n'),
isNot(hasAGoodToStringDeep));
// Single line.
expect(new _MockToStringDeep('Hello World'), isNot(hasAGoodToStringDeep));
expect(new _MockToStringDeep('Hello World\n'), isNot(hasAGoodToStringDeep));
expect(new _MockToStringDeep('Hello: World\nFoo: bar\n'),
hasAGoodToStringDeep);
expect(new _MockToStringDeep('Hello: World\nFoo: 42\n'),
hasAGoodToStringDeep);
// Contains default Object.toString().
expect(new _MockToStringDeep('Hello: World\nFoo: ${new Object()}\n'),
isNot(hasAGoodToStringDeep));
expect(new _MockToStringDeep('A\n├─B\n'), hasAGoodToStringDeep);
expect(new _MockToStringDeep('A\n├─B\n╘══════\n'), hasAGoodToStringDeep);
// Last line is all whitespace or vertical line art.
expect(new _MockToStringDeep('A\n├─B\n\n'), isNot(hasAGoodToStringDeep));
expect(new _MockToStringDeep('A\n├─B\n\n'), isNot(hasAGoodToStringDeep));
expect(new _MockToStringDeep('A\n├─B\n\n'), isNot(hasAGoodToStringDeep));
expect(new _MockToStringDeep('A\n├─B\n\n'), isNot(hasAGoodToStringDeep));
expect(new _MockToStringDeep('A\n├─B\n\n'), isNot(hasAGoodToStringDeep));
expect(new _MockToStringDeep('A\n├─B\n\n'), isNot(hasAGoodToStringDeep));
expect(new _MockToStringDeep('A\n├─B\n\n'), isNot(hasAGoodToStringDeep));
expect(new _MockToStringDeep('A\n├─B\n\n'), isNot(hasAGoodToStringDeep));
expect(new _MockToStringDeep('A\n├─B\n\n'), isNot(hasAGoodToStringDeep));
expect(new _MockToStringDeep('A\n├─B\n ││\n'), isNot(hasAGoodToStringDeep));
expect(new _MockToStringDeep(
'A\n'
'├─B\n'
'│\n'
'└─C\n'), hasAGoodToStringDeep);
// Last line is all whitespace or vertical line art.
expect(new _MockToStringDeep(
'A\n'
'├─B\n'
'│\n'), isNot(hasAGoodToStringDeep));
expect(new _MockToStringDeep.fromLines(
<String>['Paragraph#00000\n',
' │ size: (400x200)\n',
' ╘═╦══ text ═══\n',
' ║ TextSpan:\n',
' ║ "I polished up that handle so carefullee\n',
' ║ That now I am the Ruler of the Queen\'s Navee!"\n',
' ╚═══════════\n']), hasAGoodToStringDeep);
// Text span
expect(new _MockToStringDeep.fromLines(
<String>['Paragraph#00000\n',
' │ size: (400x200)\n',
' ╘═╦══ text ═══\n',
' ║ TextSpan:\n',
' ║ "I polished up that handle so carefullee\nThat now I am the Ruler of the Queen\'s Navee!"\n',
' ╚═══════════\n']), isNot(hasAGoodToStringDeep));
});
test('normalizeHashCodesEquals', () {
expect('Foo#34219', equalsIgnoringHashCodes('Foo#00000'));
expect('Foo#34219', equalsIgnoringHashCodes('Foo#12345'));
expect('Foo#34219', equalsIgnoringHashCodes('Foo#abcdf'));
expect('Foo#34219', isNot(equalsIgnoringHashCodes('Foo')));
expect('Foo#34219', isNot(equalsIgnoringHashCodes('Foo#')));
expect('Foo#34219', isNot(equalsIgnoringHashCodes('Foo#0')));
expect('Foo#34219', isNot(equalsIgnoringHashCodes('Foo#00')));
expect('Foo#34219', isNot(equalsIgnoringHashCodes('Foo#00000 ')));
expect('Foo#34219', isNot(equalsIgnoringHashCodes('Foo#000000')));
expect('Foo#34219', isNot(equalsIgnoringHashCodes('Foo#123456')));
expect('Foo#34219:', equalsIgnoringHashCodes('Foo#00000:'));
expect('Foo#34219:', isNot(equalsIgnoringHashCodes('Foo#00000')));
expect('Foo#a3b4d', equalsIgnoringHashCodes('Foo#00000'));
expect('Foo#a3b4d', equalsIgnoringHashCodes('Foo#12345'));
expect('Foo#a3b4d', equalsIgnoringHashCodes('Foo#abcdf'));
expect('Foo#a3b4d', isNot(equalsIgnoringHashCodes('Foo')));
expect('Foo#a3b4d', isNot(equalsIgnoringHashCodes('Foo#')));
expect('Foo#a3b4d', isNot(equalsIgnoringHashCodes('Foo#0')));
expect('Foo#a3b4d', isNot(equalsIgnoringHashCodes('Foo#00')));
expect('Foo#a3b4d', isNot(equalsIgnoringHashCodes('Foo#00000 ')));
expect('Foo#a3b4d', isNot(equalsIgnoringHashCodes('Foo#000000')));
expect('Foo#a3b4d', isNot(equalsIgnoringHashCodes('Foo#123456')));
expect('Foo#A3b4D', isNot(equalsIgnoringHashCodes('Foo#00000')));
expect('Foo#12345(Bar#9110f)',
equalsIgnoringHashCodes('Foo#00000(Bar#00000)'));
expect('Foo#12345(Bar#9110f)',
isNot(equalsIgnoringHashCodes('Foo#00000(Bar#)')));
expect('Foo', isNot(equalsIgnoringHashCodes('Foo#00000')));
expect('Foo#', isNot(equalsIgnoringHashCodes('Foo#00000')));
expect('Foo#3421', isNot(equalsIgnoringHashCodes('Foo#00000')));
expect('Foo#342193', isNot(equalsIgnoringHashCodes('Foo#00000')));
});
test('moreOrLessEquals', () {
expect(0.0, moreOrLessEquals(1e-11));
expect(1e-11, moreOrLessEquals(0.0));
......
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