Add link to example usage in data extensions editor

This will allow a user to click on the number of usages to jump to an
example usage in the code.

extensions/ql-vscode/src/data-extensions-editor/data-extensions-editor-view.ts

@@ -1,4 +1,9 @@
-import { CancellationTokenSource, ExtensionContext, ViewColumn } from "vscode";
+import {
+  CancellationTokenSource,
+  ExtensionContext,
+  ViewColumn,
+  window,
+} from "vscode";
 import { AbstractWebview, WebviewPanelConfig } from "../abstract-webview";
 import {
   FromDataExtensionsEditorMessage,
@@ -14,6 +19,9 @@ import { dump } from "js-yaml";
 import { getOnDiskWorkspaceFolders } from "../helpers";
 import { DatabaseItem } from "../local-databases";
 import { CodeQLCliServer } from "../cli";
+import { assertNever } from "../pure/helpers-pure";
+import { ResolvableLocationValue } from "../pure/bqrs-cli-types";
+import { showResolvableLocation } from "../interface-utils";
 
 export class DataExtensionsEditorView extends AbstractWebview<
   ToDataExtensionsEditorMessage,
@@ -57,9 +65,13 @@ export class DataExtensionsEditorView extends AbstractWebview<
       case "viewLoaded":
         await this.onWebViewLoaded();
 
+        break;
+      case "jumpToUsage":
+        await this.jumpToUsage(msg.location);
+
         break;
       default:
-        throw new Error("Unexpected message type");
+        assertNever(msg);
     }
   }
 
@@ -69,6 +81,26 @@ export class DataExtensionsEditorView extends AbstractWebview<
     await this.loadExternalApiUsages();
   }
 
+  protected async jumpToUsage(
+    location: ResolvableLocationValue,
+  ): Promise<void> {
+    try {
+      await showResolvableLocation(location, this.databaseItem);
+    } catch (e) {
+      if (e instanceof Error) {
+        if (e.message.match(/File not found/)) {
+          void window.showErrorMessage(
+            "Original file of this result is not in the database's source archive.",
+          );
+        } else {
+          void extLogger.log(`Unable to handleMsgFromView: ${e.message}`);
+        }
+      } else {
+        void extLogger.log(`Unable to handleMsgFromView: ${e}`);
+      }
+    }
+  }
+
   protected async loadExternalApiUsages(): Promise<void> {
     const queryResult = await this.runQuery();
     if (!queryResult) {

extensions/ql-vscode/src/pure/interface-types.ts

@@ -492,8 +492,15 @@ export interface ShowProgressMessage {
   message: string;
 }
 
+export interface JumpToUsageMessage {
+  t: "jumpToUsage";
+  location: ResolvableLocationValue;
+}
+
 export type ToDataExtensionsEditorMessage =
   | SetExternalApiResultsMessage
   | ShowProgressMessage;
 
-export type FromDataExtensionsEditorMessage = ViewLoadedMsg;
+export type FromDataExtensionsEditorMessage =
+  | ViewLoadedMsg
+  | JumpToUsageMessage;

extensions/ql-vscode/src/view/data-extensions-editor/MethodRow.tsx

@@ -12,6 +12,7 @@ import {
 import * as React from "react";
 import { useCallback, useMemo } from "react";
 import styled from "styled-components";
+import { vscode } from "../vscode-api";
 
 const Dropdown = styled(VSCodeDropdown)`
   width: 100%;
@@ -29,6 +30,13 @@ const SupportedUnsupportedSpan = styled.span<SupportedUnsupportedSpanProps>`
   color: ${(props) => (props.supported ? "green" : "red")};
 `;
 
+const UsagesButton = styled.button`
+  color: var(--vscode-editor-foreground);
+  background-color: transparent;
+  border: none;
+  cursor: pointer;
+`;
+
 type Props = {
   method: ExternalApiUsage;
   model: ModeledMethod | undefined;
@@ -105,6 +113,13 @@ export const MethodRow = ({ method, model, onChange }: Props) => {
     [onChange, method, model],
   );
 
+  const jumpToUsage = useCallback(() => {
+    vscode.postMessage({
+      t: "jumpToUsage",
+      location: method.usages[0].url,
+    });
+  }, [method]);
+
   return (
     <VSCodeDataGridRow>
       <VSCodeDataGridCell gridColumn={1}>
@@ -119,7 +134,9 @@ export const MethodRow = ({ method, model, onChange }: Props) => {
         </SupportedUnsupportedSpan>
       </VSCodeDataGridCell>
       <VSCodeDataGridCell gridColumn={3}>
-        {method.usages.length}
+        <UsagesButton onClick={jumpToUsage}>
+          {method.usages.length}
+        </UsagesButton>
       </VSCodeDataGridCell>
       <VSCodeDataGridCell gridColumn={4}>
         {(!method.supported || (model && model?.type !== "none")) && (