Add the step_nav component to be used by the Pipeline Wizard

Signed-off-by: Janis Altherr <jaltherr@gitlab.com>

app/assets/javascripts/pipeline_wizard/components/step_nav.vue

+<script>
+import { GlButton } from '@gitlab/ui';
+
+export default {
+  name: 'StepNav',
+  components: {
+    GlButton,
+  },
+  props: {
+    showBackButton: {
+      type: Boolean,
+      required: false,
+      default: false,
+    },
+    showNextButton: {
+      type: Boolean,
+      required: false,
+      default: false,
+    },
+    nextButtonEnabled: {
+      type: Boolean,
+      required: false,
+      default: true,
+    },
+  },
+};
+</script>
+
+<template>
+  <div>
+    <slot name="before"></slot>
+    <gl-button
+      v-if="showBackButton"
+      category="secondary"
+      data-testid="back-button"
+      @click="$emit('back')"
+    >
+      {{ __('Back') }}
+    </gl-button>
+    <gl-button
+      v-if="showNextButton"
+      :disabled="!nextButtonEnabled"
+      category="primary"
+      data-testid="next-button"
+      variant="confirm"
+      @click="$emit('next')"
+    >
+      {{ __('Next') }}
+    </gl-button>
+    <slot name="after"></slot>
+  </div>
+</template>
+
+<style scoped></style>

spec/frontend/pipeline_wizard/components/step_nav_spec.js

+import { mountExtended } from 'helpers/vue_test_utils_helper';
+import StepNav from '~/pipeline_wizard/components/step_nav.vue';
+
+describe('Pipeline Wizard - Step Navigation Component', () => {
+  const defaultProps = { showBackButton: true, showNextButton: true };
+
+  let wrapper;
+  let prevButton;
+  let nextButton;
+
+  const createComponent = (props = {}) => {
+    wrapper = mountExtended(StepNav, {
+      propsData: {
+        ...defaultProps,
+        ...props,
+      },
+    });
+    prevButton = wrapper.findByTestId('back-button');
+    nextButton = wrapper.findByTestId('next-button');
+  };
+
+  afterEach(() => {
+    wrapper.destroy();
+  });
+
+  it.each`
+    scenario                       | showBackButton | showNextButton
+    ${'does not show prev button'} | ${false}       | ${false}
+    ${'has prev, but not next'}    | ${true}        | ${false}
+    ${'has next, but not prev'}    | ${false}       | ${true}
+    ${'has both next and prev'}    | ${true}        | ${true}
+  `('$scenario', async ({ showBackButton, showNextButton }) => {
+    createComponent({ showBackButton, showNextButton });
+
+    expect(prevButton.exists()).toBe(showBackButton);
+    expect(nextButton.exists()).toBe(showNextButton);
+  });
+
+  it('shows the expected button text', () => {
+    createComponent();
+
+    expect(prevButton.text()).toBe('Back');
+    expect(nextButton.text()).toBe('Next');
+  });
+
+  it('emits "back" events when clicking prev button', async () => {
+    createComponent();
+
+    await prevButton.trigger('click');
+    expect(wrapper.emitted().back.length).toBe(1);
+  });
+
+  it('emits "next" events when clicking next button', async () => {
+    createComponent();
+
+    await nextButton.trigger('click');
+    expect(wrapper.emitted().next.length).toBe(1);
+  });
+
+  it('enables the next button if nextButtonEnabled ist set to true', async () => {
+    createComponent({ nextButtonEnabled: true });
+
+    expect(nextButton.attributes('disabled')).not.toBe('disabled');
+  });
+
+  it('disables the next button if nextButtonEnabled ist set to false', async () => {
+    createComponent({ nextButtonEnabled: false });
+
+    expect(nextButton.attributes('disabled')).toBe('disabled');
+  });
+
+  it('does not emit "next" event when clicking next button while nextButtonEnabled ist set to false', async () => {
+    createComponent({ nextButtonEnabled: false });
+
+    await nextButton.trigger('click');
+
+    expect(wrapper.emitted().next).toBe(undefined);
+  });
+});