Add diagnostics to suggest box

This adds the ability for consumers of the suggest box to add
diagnostics to the suggest box. When a diagnostic is returned for a
value, the input will be shown with a red border.

extensions/ql-vscode/src/stories/common/SuggestBox.stories.tsx

@@ -5,6 +5,7 @@ import { styled } from "styled-components";
 import { Codicon } from "../../view/common";
 import { SuggestBox as SuggestBoxComponent } from "../../view/common/SuggestBox/SuggestBox";
 import { useCallback, useState } from "react";
+import type { Diagnostic } from "../../view/common/SuggestBox/diagnostics";
 
 export default {
   title: "Suggest Box",
@@ -141,6 +142,25 @@ export const AccessPath = Template.bind({});
 AccessPath.args = {
   options: suggestedOptions,
   parseValueToTokens: (value: string) => value.split("."),
+  validateValue: (value: string) => {
+    let index = value.indexOf("|");
+
+    const diagnostics: Diagnostic[] = [];
+
+    while (index !== -1) {
+      index = value.indexOf("|", index + 1);
+
+      diagnostics.push({
+        message: "This cannot contain |",
+        range: {
+          start: index,
+          end: index + 1,
+        },
+      });
+    }
+
+    return diagnostics;
+  },
   getIcon: (option: StoryOption) => <Icon name={option.icon} />,
   getDetails: (option: StoryOption) => option.details,
 };

extensions/ql-vscode/src/view/common/SuggestBox/SuggestBox.tsx

@@ -13,16 +13,24 @@ import {
   useListNavigation,
   useRole,
 } from "@floating-ui/react";
-import { styled } from "styled-components";
+import { css, styled } from "styled-components";
 import { VSCodeTextField } from "@vscode/webview-ui-toolkit/react";
 import type { Option } from "./options";
 import { findMatchingOptions } from "./options";
 import { SuggestBoxItem } from "./SuggestBoxItem";
+import type { Diagnostic } from "./diagnostics";
 
-const Input = styled(VSCodeTextField)`
+const Input = styled(VSCodeTextField)<{ $error: boolean }>`
   width: 430px;
 
   font-family: var(--vscode-editor-font-family);
+
+  ${(props) =>
+    props.$error &&
+    css`
+      --dropdown-border: var(--vscode-inputValidation-errorBorder);
+      --focus-border: var(--vscode-inputValidation-errorBorder);
+    `}
 `;
 
 const Container = styled.div`
@@ -50,7 +58,10 @@ const NoSuggestionsText = styled.div`
   padding-left: 22px;
 `;
 
-export type SuggestBoxProps<T extends Option<T>> = {
+export type SuggestBoxProps<
+  T extends Option<T>,
+  D extends Diagnostic = Diagnostic,
+> = {
   value?: string;
   onChange: (value: string) => void;
   options: T[];
@@ -62,6 +73,12 @@ export type SuggestBoxProps<T extends Option<T>> = {
    */
   parseValueToTokens: (value: string) => string[];
 
+  /**
+   * Validate the value. This is used to show syntax errors in the input.
+   * @param value The user-entered value to validate.
+   */
+  validateValue?: (value: string) => D[];
+
   /**
    * Get the icon to display for an option.
    * @param option The option to get the icon for.
@@ -83,20 +100,29 @@ export type SuggestBoxProps<T extends Option<T>> = {
    * for easier testing.
    * @param props The props returned by `getReferenceProps` of {@link useInteractions}
    */
-  renderInputComponent?: (props: Record<string, unknown>) => ReactNode;
+  renderInputComponent?: (
+    props: Record<string, unknown>,
+    hasError: boolean,
+  ) => ReactNode;
 };
 
-export const SuggestBox = <T extends Option<T>>({
+export const SuggestBox = <
+  T extends Option<T>,
+  D extends Diagnostic = Diagnostic,
+>({
   value = "",
   onChange,
   options,
   parseValueToTokens,
+  validateValue,
   getIcon,
   getDetails,
   disabled,
   "aria-label": ariaLabel,
-  renderInputComponent = (props) => <Input {...props} />,
-}: SuggestBoxProps<T>) => {
+  renderInputComponent = (props, hasError) => (
+    <Input {...props} $error={hasError} />
+  ),
+}: SuggestBoxProps<T, D>) => {
   const [isOpen, setIsOpen] = useState(false);
   const [activeIndex, setActiveIndex] = useState<number | null>(null);
 
@@ -151,6 +177,13 @@ export const SuggestBox = <T extends Option<T>>({
     return findMatchingOptions(options, parseValueToTokens(value));
   }, [options, value, parseValueToTokens]);
 
+  const diagnostics = useMemo(
+    () => validateValue?.(value) ?? [],
+    [validateValue, value],
+  );
+
+  const hasSyntaxError = diagnostics.length > 0;
+
   useEffect(() => {
     if (disabled) {
       setIsOpen(false);
@@ -180,6 +213,7 @@ export const SuggestBox = <T extends Option<T>>({
           },
           disabled,
         }),
+        hasSyntaxError,
       )}
       {isOpen && (
         <FloatingPortal>

extensions/ql-vscode/src/view/common/SuggestBox/diagnostics.ts

@@ -0,0 +1,21 @@
+/**
+ * A range of characters in a value. The start position is inclusive, the end position is exclusive.
+ */
+type DiagnosticRange = {
+  /**
+   * Zero-based index of the first character of the token.
+   */
+  start: number;
+  /**
+   * Zero-based index of the character after the last character of the token.
+   */
+  end: number;
+};
+
+/**
+ * A diagnostic message.
+ */
+export type Diagnostic = {
+  range: DiagnosticRange;
+  message: string;
+};