fix(theming): Adjust dark theme to be accessible adjust cypress tests

Also fix warning text color for bright / default theme on blurry background

Signed-off-by: Ferdinand Thiessen <opensource@fthiessen.de>

2 files changed, 154 insertions, 0 deletions

diff --git a/cypress/e2e/theming/a11y-color-contrast.cy.ts b/cypress/e2e/theming/a11y-color-contrast.cy.ts
new file mode 100644
index 00000000000..03a6814ea1f
--- /dev/null
+++ b/cypress/e2e/theming/a11y-color-contrast.cy.ts
@@ -0,0 +1,153 @@
+const themesToTest = ['light', 'dark', 'light-highcontrast', 'dark-highcontrast']
+
+const testCases = {
+	'Main text': {
+		foregroundColors: [
+			'color-main-text',
+			// 'color-text-light', deprecated
+			// 'color-text-lighter', deprecated
+			'color-text-maxcontrast',
+		],
+		backgroundColors: [
+			'color-main-background',
+			'color-background-hover',
+			'color-background-dark',
+			// 'color-background-darker', this should only be used for elements not for text
+		],
+	},
+	'blurred background': {
+		foregroundColors: [
+			'color-main-text',
+			'color-text-maxcontrast-blur',
+		],
+		backgroundColors: [
+			'color-main-background-blur',
+		],
+	},
+	Primary: {
+		foregroundColors: [
+			'color-primary-text',
+		],
+		backgroundColors: [
+			// 'color-primary-default', this should only be used for elements not for text!
+			// 'color-primary-hover', this should only be used for elements and not for text!
+			'color-primary',
+		],
+	},
+	'Primary light': {
+		foregroundColors: [
+			'color-primary-light-text',
+		],
+		backgroundColors: [
+			'color-primary-light',
+			'color-primary-light-hover',
+		],
+	},
+	'Primary element': {
+		foregroundColors: [
+			'color-primary-element-text',
+			'color-primary-element-text-dark',
+		],
+		backgroundColors: [
+			'color-primary-element',
+			'color-primary-element-hover',
+		],
+	},
+	'Primary element light': {
+		foregroundColors: [
+			'color-primary-element-light-text',
+		],
+		backgroundColors: [
+			'color-primary-element-light',
+			'color-primary-element-light-hover',
+		],
+	},
+	'Servity information texts': {
+		foregroundColors: [
+			'color-error-text',
+			'color-warning-text',
+			'color-success-text',
+			'color-info-text',
+		],
+		backgroundColors: [
+			'color-main-background',
+			'color-background-hover',
+			'color-main-background-blur',
+		],
+	},
+}
+
+/**
+ * Create a wrapper element with color and background set
+ *
+ * @param foreground The foreground color (css variable without leading --)
+ * @param background The background color
+ */
+function createTestCase(foreground: string, background: string) {
+	const wrapper = document.createElement('div')
+	wrapper.style.padding = '14px'
+	wrapper.style.color = `var(--${foreground})`
+	wrapper.style.backgroundColor = `var(--${background})`
+	if (background.includes('blur')) {
+		wrapper.style.backdropFilter = 'var(--filter-background-blur)'
+	}
+
+	const testCase = document.createElement('div')
+	testCase.innerText = `${foreground} ${background}`
+	testCase.setAttribute('data-cy-testcase', '')
+
+	wrapper.appendChild(testCase)
+	return wrapper
+}
+
+describe('Accessibility of Nextcloud theming colors', () => {
+	for (const theme of themesToTest) {
+		context(`Theme: ${theme}`, () => {
+			before(() => {
+				cy.createRandomUser().then(($user) => {
+					// set user theme
+					cy.runOccCommand(`user:setting -- '${$user.userId}' theming enabled-themes '["${theme}"]'`)
+					cy.login($user)
+					cy.visit('/')
+					cy.injectAxe({ axeCorePath: 'node_modules/axe-core/axe.min.js' })
+				})
+			})
+
+			beforeEach(() => {
+				cy.document().then(doc => {
+					// Unset background image and thus use background-color for testing blur background (images do not work with axe-core)
+					doc.body.style.backgroundImage = 'unset'
+
+					const root = doc.querySelector('main')
+					if (root === null) {
+						throw new Error('No test root found')
+					}
+					root.innerHTML = ''
+				})
+			})
+
+			for (const [name, { backgroundColors, foregroundColors }] of Object.entries(testCases)) {
+				context(`Accessibility of CSS color variables for ${name}`, () => {
+					for (const foreground of foregroundColors) {
+						for (const background of backgroundColors) {
+							it(`color contrast of ${foreground} on ${background}`, () => {
+								cy.document().then(doc => {
+									const element = createTestCase(foreground, background)
+									const root = doc.querySelector('main')
+									// eslint-disable-next-line no-unused-expressions
+									expect(root).not.to.be.undefined
+									// eslint-disable-next-line @typescript-eslint/no-non-null-assertion
+									root!.appendChild(element)
+
+									cy.checkA11y('[data-cy-testcase]', {
+										runOnly: ['color-contrast'],
+									})
+								})
+							})
+						}
+					}
+				})
+			}
+		})
+	}
+})
diff --git a/cypress/support/e2e.ts b/cypress/support/e2e.ts
index 2bc91f83ebd..6cf83e94961 100644
--- a/cypress/support/e2e.ts
+++ b/cypress/support/e2e.ts
@@ -19,6 +19,7 @@
  * along with this program. If not, see <http://www.gnu.org/licenses/>.
  *
  */
+import 'cypress-axe'
 import './commands.ts'
 
 // Fix ResizeObserver loop limit exceeded happening in Cypress only