Config file

AMA comes with predefined rules and severity for the built-in components and hooks. Those rules have been created to improve the accessibility of those elements and should always be respected.

Customizing log levels can be done via the ama.config.json file to handle edge cases that are out of our control, and require breaking a rule or two.

info

The library does not perform any accessibility checks on the production build!

The log levels

AMA guidelines are categorised as:

• MUST and MUST NOT: Those best practices are enforced and AMA overlays an error when fail
• SHOULD and SHOULD_NOT: Those best practices are preferred and AMA prints only prints a warning message when fail

The possible log levels are:

• error: The AMA error overlay when a check fails
• warn: A console.warn is performed when a check fails

AMA Rules

Log key	Guideline	Default	Can override
BOTTOM_SHEET_CLOSE_ACTION	MUST	error
CONTRAST_FAILED	MUST	error
CONTRAST_FAILED_AAA	SHOULD	warn
FLATLIST_NO_COUNT_IN_SINGULAR_MESSAGE	SHOULD	warn
FLATLIST_NO_COUNT_IN_PLURAL_MESSAGE	MUST	error
MINIMUM_SIZE	MUST	error
NO_ACCESSIBILITY_LABEL1	MUST	error
NO_ACCESSIBILITY_ROLE 1	MUST	error
NO_FORM_LABEL	MUST	error
NO_FORM_ERROR	MUST	error
NO_KEYBOARD_TRAP 1	MUST NOT	error
UPPERCASE_TEXT_NO_ACCESSIBILITY_LABEL	MUST NOT	error
NO_UPPERCASE_TEXT	MUST NOT	error

note

Rules marked with are considered bad practices and cannot be turned off!

Constants

Elements that perform a contrast check do it on all the children up to the level specified by CONTRAST_CHECKER_MAX_DEPTH.

Constant key	Default value
CONTRAST_CHECKER_MAX_DEPTH	5

{
  "CONTRAST_CHECKER_MAX_DEPTH": 0
}

tip

This can be turned off by specifying a level of 0

accessibilityLabelExceptions

AMA performs various checks, including one for uppercase. This rule allows specifying a list of approved all-caps accessibility labels.

{
  "accessibilityLabelExceptions": ["FAQ"]
}

Customising the log levels

Create a JSON file called ama.config.json in the project's root folder to customise the log rules, then specify the custom log level for the wanted key.

Example

The JSON file does not need to contain all log keys. AMA uses the default rule if a key is not present:

{
  "CONTRAST_FAILED": "warn",
  "CONTRAST_CHECKER_MAX_DEPTH": 0,
  "accessibilityLabelExceptions": ["FAQ"]
}

caution

Whenever the ama.rules.json file is updated, update the copy within the node_modules folder and restart the development server.

cp ama.rules.json node_modules/react-native-ama/

yarn start

---

1. The rule cannot be overridden↩