[Text field] Pass step to input

UNRELEASED.md

@@ -23,6 +23,7 @@ Use [the changelog guidelines](https://git.io/polaris-changelog-guidelines) to f
 - Fixed `Checkbox` from losing focus when quickly toggled ([#717](https://github.com/Shopify/polaris-react/pull/717))
 - Fixed the console error in the `PositionedOverlay` test environment ([#758](https://github.com/Shopify/polaris-react/pull/758))
 - Fixed `ResourceList` not rendering a header after initial load (thanks to [@andrewpye](https://github.com/andrewpye) for the [original issue](https://github.com/Shopify/polaris-react/issues/735))
+- Fixed `TextField` not passing `step` to the input ([#829](https://github.com/Shopify/polaris-react/pull/829))
 
 ### Documentation
 

src/components/TextField/TextField.tsx

@@ -168,6 +168,7 @@ export default class TextField extends React.PureComponent<Props, State> {
       autoComplete,
       min,
       max,
+      step,
       minLength,
       maxLength,
       spellCheck,
@@ -264,6 +265,7 @@ export default class TextField extends React.PureComponent<Props, State> {
       ref: this.setInput,
       min,
       max,
+      step,
       minLength,
       maxLength,
       spellCheck,

src/components/TextField/tests/TextField.test.tsx

@@ -369,6 +369,20 @@ describe('<TextField />', () => {
         expect(spy).toHaveBeenCalledWith('1', 'MyTextField');
       });
 
+      it('passes the step prop to the input', () => {
+        const element = mountWithAppProvider(
+          <TextField
+            id="MyTextField"
+            label="TextField"
+            type="number"
+            step={6}
+            value="4"
+            onChange={noop}
+          />,
+        );
+        expect(element.find('input').prop('step')).toBe(6);
+      });
+
       it('uses the step prop when incrementing', () => {
         const spy = jest.fn();
         const element = mountWithAppProvider(