diff --git a/extensions/ql-vscode/src/view/common/SuggestBox/SuggestBox.tsx b/extensions/ql-vscode/src/view/common/SuggestBox/SuggestBox.tsx
index 544de25c1..0e338892f 100644
--- a/extensions/ql-vscode/src/view/common/SuggestBox/SuggestBox.tsx
+++ b/extensions/ql-vscode/src/view/common/SuggestBox/SuggestBox.tsx
@@ -1,5 +1,5 @@
 import type { FormEvent, ReactNode } from "react";
-import { useCallback, useMemo, useRef, useState, useEffect } from "react";
+import { useCallback, useEffect, useMemo, useRef, useState } from "react";
 import {
   autoUpdate,
   flip,
@@ -50,7 +50,7 @@ const NoSuggestionsText = styled.div`
   padding-left: 22px;
 `;
 
-type Props<T extends Option<T>> = {
+export type SuggestBoxProps<T extends Option<T>> = {
   value?: string;
   onChange: (value: string) => void;
   options: T[];
@@ -76,6 +76,14 @@ type Props<T extends Option<T>> = {
   disabled?: boolean;
 
   "aria-label"?: string;
+
+  /**
+   * Can be used to render a different component for the input. This is used
+   * in testing to use default HTML components rather than the VSCodeTextField
+   * for easier testing.
+   * @param props The props returned by `getReferenceProps` of {@link useInteractions}
+   */
+  renderInputComponent?: (props: Record<string, unknown>) => ReactNode;
 };
 
 export const SuggestBox = <T extends Option<T>>({
@@ -87,7 +95,8 @@ export const SuggestBox = <T extends Option<T>>({
   getDetails,
   disabled,
   "aria-label": ariaLabel,
-}: Props<T>) => {
+  renderInputComponent = (props) => <Input {...props} />,
+}: SuggestBoxProps<T>) => {
   const [isOpen, setIsOpen] = useState(false);
   const [activeIndex, setActiveIndex] = useState<number | null>(null);
 
@@ -150,8 +159,8 @@ export const SuggestBox = <T extends Option<T>>({
 
   return (
     <>
-      <Input
-        {...getReferenceProps({
+      {renderInputComponent(
+        getReferenceProps({
           ref: refs.setReference,
           value,
           onInput: handleInput,
@@ -170,8 +179,8 @@ export const SuggestBox = <T extends Option<T>>({
             }
           },
           disabled,
-        })}
-      />
+        }),
+      )}
       {isOpen && (
         <FloatingPortal>
           {value && suggestionItems.length === 0 && (
diff --git a/extensions/ql-vscode/src/view/common/SuggestBox/__tests__/SuggestBox.test.tsx b/extensions/ql-vscode/src/view/common/SuggestBox/__tests__/SuggestBox.test.tsx
new file mode 100644
index 000000000..21225f898
--- /dev/null
+++ b/extensions/ql-vscode/src/view/common/SuggestBox/__tests__/SuggestBox.test.tsx
@@ -0,0 +1,240 @@
+import { render as reactRender, screen } from "@testing-library/react";
+import type { SuggestBoxProps } from "../SuggestBox";
+import { SuggestBox } from "../SuggestBox";
+import { userEvent } from "@testing-library/user-event";
+
+type TestOption = {
+  label: string;
+  value: string;
+  followup?: TestOption[];
+};
+
+const options: TestOption[] = [
+  {
+    label: "Argument[self]",
+    value: "Argument[self]",
+  },
+  {
+    label: "Argument[0]",
+    value: "Argument[0]",
+    followup: [
+      {
+        label: "Element[0]",
+        value: "Argument[0].Element[0]",
+      },
+      {
+        label: "Element[1]",
+        value: "Argument[0].Element[1]",
+      },
+      {
+        label: "Element[any]",
+        value: "Argument[0].Element[any]",
+      },
+    ],
+  },
+  {
+    label: "Argument[1]",
+    value: "Argument[1]",
+  },
+  {
+    label: "Argument[text_rep:]",
+    value: "Argument[text_rep:]",
+  },
+  {
+    label: "Argument[block]",
+    value: "Argument[block]",
+    followup: [
+      {
+        label: "Parameter[0]",
+        value: "Argument[block].Parameter[0]",
+        followup: [
+          {
+            label: "Element[:query]",
+            value: "Argument[block].Parameter[0].Element[:query]",
+          },
+          {
+            label: "Element[:parameters]",
+            value: "Argument[block].Parameter[0].Element[:parameters]",
+          },
+        ],
+      },
+      {
+        label: "Parameter[1]",
+        value: "Argument[block].Parameter[1]",
+        followup: [
+          {
+            label: "Field[@query]",
+            value: "Argument[block].Parameter[1].Field[@query]",
+          },
+        ],
+      },
+    ],
+  },
+  {
+    label: "ReturnValue",
+    value: "ReturnValue",
+  },
+];
+
+describe("SuggestBox", () => {
+  const onChange = jest.fn();
+  const parseValueToTokens = jest.fn();
+  const render = (props?: Partial<SuggestBoxProps<TestOption>>) =>
+    reactRender(
+      <SuggestBox
+        options={options}
+        onChange={onChange}
+        parseValueToTokens={parseValueToTokens}
+        renderInputComponent={(props) => <input {...props} />}
+        {...props}
+      />,
+    );
+
+  beforeEach(() => {
+    onChange.mockReset();
+    parseValueToTokens
+      .mockReset()
+      .mockImplementation((value: string) => value.split("."));
+  });
+
+  it("does not render the options by default", () => {
+    render();
+
+    expect(screen.queryByRole("option")).not.toBeInTheDocument();
+  });
+
+  it("renders the options after clicking on the text field", async () => {
+    render();
+
+    await userEvent.click(screen.getByRole("combobox"));
+
+    expect(screen.getAllByRole("option")).toHaveLength(options.length);
+  });
+
+  it("calls onChange after entering text", async () => {
+    render({
+      value: "Argument[block]",
+    });
+
+    await userEvent.type(screen.getByRole("combobox"), ".");
+
+    expect(onChange).toHaveBeenCalledWith("Argument[block].");
+  });
+
+  it("calls onChange after clearing text", async () => {
+    render({
+      value: "Argument[block].",
+    });
+
+    await userEvent.clear(screen.getByRole("combobox"));
+
+    expect(onChange).toHaveBeenCalledWith("");
+  });
+
+  it("renders matching options with a single token", async () => {
+    render({
+      value: "block",
+    });
+
+    await userEvent.click(screen.getByRole("combobox"));
+
+    expect(screen.getByRole("option")).toHaveTextContent("Argument[block]");
+  });
+
+  it("renders followup options with a token and an empty token", async () => {
+    render({
+      value: "Argument[block].",
+    });
+
+    await userEvent.click(screen.getByRole("combobox"));
+
+    expect(screen.getAllByRole("option")).toHaveLength(2);
+  });
+
+  it("renders matching followup options with two tokens", async () => {
+    render({
+      value: "Argument[block].1",
+    });
+
+    await userEvent.click(screen.getByRole("combobox"));
+
+    expect(screen.getByRole("option")).toHaveTextContent("Parameter[1]");
+  });
+
+  it("closes the options when selecting an option", async () => {
+    render({
+      value: "Argument[block].1",
+    });
+
+    await userEvent.click(screen.getByRole("combobox"));
+    await userEvent.keyboard("{Enter}");
+
+    expect(screen.queryByRole("option")).not.toBeInTheDocument();
+  });
+
+  it("shows no suggestions with no matching followup options", async () => {
+    render({
+      value: "Argument[block].block",
+    });
+
+    await userEvent.click(screen.getByRole("combobox"));
+
+    expect(screen.queryByRole("option")).not.toBeInTheDocument();
+    expect(screen.getByText("No suggestions.")).toBeInTheDocument();
+  });
+
+  it("can navigate the options using the keyboard", async () => {
+    render({
+      value: "",
+    });
+
+    await userEvent.click(screen.getByRole("combobox"));
+    await userEvent.keyboard(
+      "{ArrowDown}{ArrowDown}{ArrowUp}{ArrowDown}{ArrowDown}{Enter}",
+    );
+
+    expect(onChange).toHaveBeenCalledWith("Argument[text_rep:]");
+    expect(screen.queryByRole("option")).not.toBeInTheDocument();
+  });
+
+  it("can use loop navigation when using the keyboard", async () => {
+    render({
+      value: "",
+    });
+
+    await userEvent.click(screen.getByRole("combobox"));
+    await userEvent.keyboard("{ArrowUp}{ArrowUp}{Enter}");
+
+    expect(onChange).toHaveBeenCalledWith("Argument[block]");
+    expect(screen.queryByRole("option")).not.toBeInTheDocument();
+  });
+
+  it("can close the options using escape", async () => {
+    render({
+      value: "",
+    });
+
+    await userEvent.click(screen.getByRole("combobox"));
+
+    expect(screen.getAllByRole("option")).toHaveLength(options.length);
+
+    await userEvent.keyboard("{Escape}");
+
+    expect(screen.queryByRole("option")).not.toBeInTheDocument();
+  });
+
+  it("opens the options when using backspace on a selected option", async () => {
+    render({
+      value: "Argument[block].1",
+    });
+
+    await userEvent.click(screen.getByRole("combobox"));
+    await userEvent.keyboard("{Enter}");
+
+    expect(screen.queryByRole("option")).not.toBeInTheDocument();
+
+    await userEvent.keyboard("{Backspace}");
+
+    expect(screen.getAllByRole("option")).toHaveLength(1);
+  });
+});