Jan Mewes

Posted on Dec 7, 2021 • Edited on Dec 8, 2021

Built-in Flutter Widget Finders

#flutter

This blog post provides an overview of the options for querying widgets in widget tests which are available by default in the flutter_test library.

Identifier
- Find by key
Text
Type
Hierarchy
- Find by descendant
- Find by ancestor
Miscellaneous
References
Credits

Identifier

Find by key

find.byKey(const ValueKey('continue'))

Text

Find by text

find.text('Back')

Find by rich text

find.text('Close', findRichText: true)

Find by partial text

find.textContain('Back')

Find by matching text

find.textContain(RegExp(r'(\w+)'))

Type

Find by class name

find.byType(IconButton)

Find by icon

find.byIcon(Icons.inbox)

Find by element type

find.byElementType(SingleChildRenderObjectElement)

Hierarchy

Find by descendant

find.descendant(
  of: find.byType(TextField),
  matching: find.text('Key 1'),
)

Find by ancestor

find.ancestor(
  of: find.text('faded'),
  matching: find.byType('Opacity'),
)

Miscellaneous

Find by semantics label

find.bySemanticsLabel('Back')

Find by image

find.image(FileImage(File(filePath)))

Find by tooltip

find.byTooltip('Back')

Find by widget predicate

find.byWidgetPredicate(
 (Widget widget) => widget is Tooltip && widget.message == 'Back',
 description: 'widget with tooltip "Back"',
)

Find by element predicate

find.byElementPredicate(
  // finds elements of type SingleChildRenderObjectElement, including
  // those that are actually subclasses of that type.
  // (contrast with byElementType, which only returns exact matches)
 (Element element) => element is SingleChildRenderObjectElement,
 description: '$SingleChildRenderObjectElement element',
)

References

Credits

The source code snippets are adapted from the examples in the Flutter source code which is licensed under the BSD-3-Clause License.

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