diff --git a/superset-frontend/spec/javascripts/sqllab/TemplateParamsEditor_spec.tsx b/superset-frontend/spec/javascripts/sqllab/TemplateParamsEditor_spec.tsx
new file mode 100644
index 0000000000000..ec64b9daf4505
--- /dev/null
+++ b/superset-frontend/spec/javascripts/sqllab/TemplateParamsEditor_spec.tsx
@@ -0,0 +1,57 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+import React, { ReactNode } from 'react';
+import {
+  render,
+  fireEvent,
+  getByText,
+  waitFor,
+} from 'spec/helpers/testing-library';
+import brace from 'brace';
+import { ThemeProvider, supersetTheme } from '@superset-ui/core';
+
+import TemplateParamsEditor from 'src/SqlLab/components/TemplateParamsEditor';
+
+const ThemeWrapper = ({ children }: { children: ReactNode }) => (
+  <ThemeProvider theme={supersetTheme}>{children}</ThemeProvider>
+);
+
+describe('TemplateParamsEditor', () => {
+  it('should render with a title', () => {
+    const { container } = render(
+      <TemplateParamsEditor code="FOO" language="json" onChange={() => {}} />,
+      { wrapper: ThemeWrapper },
+    );
+    expect(container.querySelector('div[role="button"]')).toBeInTheDocument();
+  });
+
+  it('should open a modal with the ace editor', async () => {
+    const { container, baseElement } = render(
+      <TemplateParamsEditor code="FOO" language="json" onChange={() => {}} />,
+      { wrapper: ThemeWrapper },
+    );
+    fireEvent.click(getByText(container, 'Parameters'));
+    const spy = jest.spyOn(brace, 'acequire');
+    spy.mockReturnValue({ setCompleters: () => 'foo' });
+    await waitFor(() => {
+      expect(baseElement.querySelector('#brace-editor')).toBeInTheDocument();
+    });
+  });
+});
diff --git a/superset-frontend/src/SqlLab/components/TemplateParamsEditor.jsx b/superset-frontend/src/SqlLab/components/TemplateParamsEditor.tsx
similarity index 75%
rename from superset-frontend/src/SqlLab/components/TemplateParamsEditor.jsx
rename to superset-frontend/src/SqlLab/components/TemplateParamsEditor.tsx
index 50d26db7295d1..5d30a88f31053 100644
--- a/superset-frontend/src/SqlLab/components/TemplateParamsEditor.jsx
+++ b/superset-frontend/src/SqlLab/components/TemplateParamsEditor.tsx
@@ -17,7 +17,6 @@
  * under the License.
  */
 import React, { useState, useEffect } from 'react';
-import PropTypes from 'prop-types';
 import Badge from 'src/components/Badge';
 import { t, styled } from '@superset-ui/core';
 import { InfoTooltipWithTrigger } from '@superset-ui/chart-controls';
@@ -26,17 +25,7 @@ import { debounce } from 'lodash';
 import ModalTrigger from 'src/components/ModalTrigger';
 import { ConfigEditor } from 'src/components/AsyncAceEditor';
 import { FAST_DEBOUNCE } from 'src/constants';
-
-const propTypes = {
-  onChange: PropTypes.func,
-  code: PropTypes.string,
-  language: PropTypes.oneOf(['yaml', 'json']),
-};
-
-const defaultProps = {
-  onChange: () => {},
-  code: '{}',
-};
+import { Tooltip } from 'src/common/components/Tooltip';
 
 const StyledConfigEditor = styled(ConfigEditor)`
   &.ace_editor {
@@ -44,8 +33,16 @@ const StyledConfigEditor = styled(ConfigEditor)`
   }
 `;
 
-function TemplateParamsEditor({ code, language, onChange }) {
-  const [parsedJSON, setParsedJSON] = useState();
+function TemplateParamsEditor({
+  code = '{}',
+  language,
+  onChange = () => {},
+}: {
+  code: string;
+  language: 'yaml' | 'json';
+  onChange: () => void;
+}) {
+  const [parsedJSON, setParsedJSON] = useState({});
   const [isValid, setIsValid] = useState(true);
 
   useEffect(() => {
@@ -53,7 +50,7 @@ function TemplateParamsEditor({ code, language, onChange }) {
       setParsedJSON(JSON.parse(code));
       setIsValid(true);
     } catch {
-      setParsedJSON({});
+      setParsedJSON({} as any);
       setIsValid(false);
     }
   }, [code]);
@@ -96,25 +93,29 @@ function TemplateParamsEditor({ code, language, onChange }) {
     <ModalTrigger
       modalTitle={t('Template parameters')}
       triggerNode={
-        <div tooltip={t('Edit template parameters')} buttonSize="small">
-          {`${t('Parameters')} `}
-          <Badge count={paramCount} />
-          {!isValid && (
-            <InfoTooltipWithTrigger
-              icon="exclamation-triangle"
-              bsStyle="danger"
-              tooltip={t('Invalid JSON')}
-              label="invalid-json"
-            />
-          )}
-        </div>
+        <Tooltip
+          id="parameters-tooltip"
+          placement="top"
+          title={t('Edit template parameters')}
+          trigger={['hover']}
+        >
+          <div role="button">
+            {`${t('Parameters')} `}
+            <Badge count={paramCount} />
+            {!isValid && (
+              <InfoTooltipWithTrigger
+                icon="exclamation-triangle"
+                bsStyle="danger"
+                tooltip={t('Invalid JSON')}
+                label="invalid-json"
+              />
+            )}
+          </div>
+        </Tooltip>
       }
       modalBody={modalBody}
     />
   );
 }
 
-TemplateParamsEditor.propTypes = propTypes;
-TemplateParamsEditor.defaultProps = defaultProps;
-
 export default TemplateParamsEditor;
diff --git a/superset-frontend/src/SqlLab/reducers/getInitialState.js b/superset-frontend/src/SqlLab/reducers/getInitialState.js
index bd74580d0c021..8052476f9bd61 100644
--- a/superset-frontend/src/SqlLab/reducers/getInitialState.js
+++ b/superset-frontend/src/SqlLab/reducers/getInitialState.js
@@ -74,13 +74,13 @@ export default function getInitialState({
         id: id.toString(),
         loaded: true,
         title: activeTab.label,
-        sql: activeTab.sql,
-        selectedText: null,
+        sql: activeTab.sql || undefined,
+        selectedText: undefined,
         latestQueryId: activeTab.latest_query
           ? activeTab.latest_query.id
           : null,
         autorun: activeTab.autorun,
-        templateParams: activeTab.template_params,
+        templateParams: activeTab.template_params || undefined,
         dbId: activeTab.database_id,
         functionNames: [],
         schema: activeTab.schema,
diff --git a/superset-frontend/src/SqlLab/reducers/getInitialState.test.ts b/superset-frontend/src/SqlLab/reducers/getInitialState.test.ts
index e08443b0598d4..94a0c6a85ec6a 100644
--- a/superset-frontend/src/SqlLab/reducers/getInitialState.test.ts
+++ b/superset-frontend/src/SqlLab/reducers/getInitialState.test.ts
@@ -36,8 +36,19 @@ const apiData = {
     username: 'some name',
   },
 };
+const apiDataWithTabState = {
+  ...apiData,
+  tab_state_ids: [{ id: 1 }],
+  active_tab: { id: 1, table_schemas: [] },
+};
 describe('getInitialState', () => {
   it('should output the user that is passed in', () => {
     expect(getInitialState(apiData).sqlLab.user.userId).toEqual(1);
   });
+  it('should return undefined instead of null for templateParams', () => {
+    expect(
+      getInitialState(apiDataWithTabState).sqlLab.queryEditors[0]
+        .templateParams,
+    ).toBeUndefined();
+  });
 });
diff --git a/superset-frontend/src/components/AsyncAceEditor/index.tsx b/superset-frontend/src/components/AsyncAceEditor/index.tsx
index 0d394d9f3d492..2a5683574a85d 100644
--- a/superset-frontend/src/components/AsyncAceEditor/index.tsx
+++ b/superset-frontend/src/components/AsyncAceEditor/index.tsx
@@ -119,6 +119,8 @@ export default function AsyncAceEditor(
           mode = inferredMode,
           theme = inferredTheme,
           tabSize = defaultTabSize,
+          defaultValue = '',
+          value = '',
           ...props
         },
         ref,
@@ -150,6 +152,8 @@ export default function AsyncAceEditor(
             mode={mode}
             theme={theme}
             tabSize={tabSize}
+            defaultValue={defaultValue}
+            value={value || ''}
             {...props}
           />
         );