[Management] Ensure non alphanumeric characters do not affect index pattern searching (#14973)

* - Fix issue with non alphanumeric characters affecting index pattern search
- Restructure and add tests

* More tests

src/core_plugins/kibana/public/management/sections/indices/create_index_pattern_wizard/step_index_pattern/append_wildcard.js

@@ -1,4 +1,5 @@
 import { uiModules } from 'ui/modules';
+import { appendWildcard } from './lib/append_wildcard';
 
 const module = uiModules.get('apps/management');
 
@@ -15,33 +16,13 @@ module.directive('appendWildcard', function () {
     require: 'ngModel',
     link: function ($scope, $elem, $attrs, $ctrl) {
       $elem.on('keydown', (e) => {
-        // https://developer.mozilla.org/en-US/docs/Web/API/KeyboardEvent/keyCode
-        // is not recommended so we need to rely on `key` but browser support
-        // is still spotty (https://developer.mozilla.org/en-US/docs/Web/API/KeyboardEvent/key)
-        // so just bail if it's not supported
-        if (!e.key) {
-          return;
-        }
-
-        if (!/[a-z0-9]/i.test(e.key)) {
-          return;
-        }
-
-        // If the user is holding down ctrl/cmd, they are performing some shortcut
-        // and do not interpret literally
-        if (e.metaKey) {
-          return;
-        }
-
-        let indexPatternName = $elem.val() + e.key;
-        if (indexPatternName.length === 1 && indexPatternName !== '*') {
-          indexPatternName += '*';
+        const newIndexPattern = appendWildcard(e, $elem.val());
+        if (newIndexPattern) {
           e.preventDefault();
-          $elem.val(indexPatternName);
+          $elem.val(newIndexPattern);
           $elem[0].setSelectionRange(1, 1);
+          $ctrl.$setViewValue(newIndexPattern);
         }
-
-        $ctrl.$setViewValue(indexPatternName);
       });
     }
   };

src/core_plugins/kibana/public/management/sections/indices/create_index_pattern_wizard/step_index_pattern/lib/__tests__/append_wildcard.js

@@ -0,0 +1,40 @@
+import expect from 'expect.js';
+
+import { appendWildcard } from '../append_wildcard';
+
+describe('append_wildcard', function () {
+  it('should add a wildcard for an alphabet input', () => {
+    [
+      'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i',
+      'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r',
+      's', 't', 'u', 'v', 'w', 'x', 'y', 'z'
+    ].forEach(char => {
+      expect(appendWildcard({ key: char }, '')).to.be(`${char}*`);
+      expect(appendWildcard({ key: char.toUpperCase() }, '')).to.be(`${char.toUpperCase()}*`);
+    });
+  });
+
+  it('should add a wildcard for a number input', () => {
+    ['0', '1', '2', '3', '4', '5', '6', '7', '8', '9'].forEach(num => {
+      expect(appendWildcard({ key: num }, '')).to.be(`${num}*`);
+    });
+  });
+
+  it('should NOT add a wildcard for a non alphanumeric input', () => {
+    ['!', '@', '#', '$', '%', '^', '&', '*', '(', ')', '-', '_', '=', '+'].forEach(char => {
+      expect(appendWildcard({ key: char }, '')).to.be(undefined);
+    });
+  });
+
+  it('should NOT add a wildcard for multi-length input', () => {
+    expect(appendWildcard({ key: 'Tab' }, '')).to.be(undefined);
+  });
+
+  it('should NOT add a wildcard if the value is longer than 1 character', () => {
+    expect(appendWildcard({ key: 'a' }, 'b')).to.be(undefined);
+  });
+
+  it('should NOT add a wildcard if the input is a wildcard', () => {
+    expect(appendWildcard({ key: '*' }, '')).to.be(undefined);
+  });
+});

src/core_plugins/kibana/public/management/sections/indices/create_index_pattern_wizard/step_index_pattern/lib/append_wildcard.js

@@ -0,0 +1,30 @@
+export const appendWildcard = (keyboardEvent, value) => {
+  const { key: keyPressed, metaKey } = keyboardEvent;
+
+  // https://developer.mozilla.org/en-US/docs/Web/API/KeyboardEvent/keyCode
+  // is not recommended so we need to rely on `key` but browser support
+  // is still spotty (https://developer.mozilla.org/en-US/docs/Web/API/KeyboardEvent/key)
+  // so just bail if it's not supported
+  if (!keyPressed) {
+    return;
+  }
+
+  // If the user is holding down ctrl/cmd, they are performing some shortcut
+  // and do not interpret literally
+  if (metaKey) {
+    return;
+  }
+
+  // If it's not a letter, number or is something longer, reject it
+  if (!/[a-z0-9]/i.test(keyPressed) || keyPressed.length !== 1) {
+    return;
+  }
+
+  let newValue = value + keyPressed;
+  if (newValue.length !== 1 || newValue === '*') {
+    return;
+  }
+
+  newValue += '*';
+  return newValue;
+};