Add search features API

src/client/api/search.ts

@@ -0,0 +1,42 @@
+import { from, Observable, Subscription } from 'rxjs'
+import { ExtSearchFeaturesAPI } from 'src/extension/api/search'
+import { Connection } from 'src/protocol/jsonrpc2/connection'
+import { createProxyAndHandleRequests } from '../../common/proxy'
+import { FeatureProviderRegistry } from '../providers/registry'
+import { TransformQuerySignature } from '../providers/search'
+import { SubscriptionMap } from './common'
+
+export interface SearchFeaturesAPI {
+    $registerQueryTransformProvider(id: number): void
+    $unregister(id: number): void
+}
+
+export class SearchFeatures implements SearchFeaturesAPI {
+    private subscriptions = new Subscription()
+    private registrations = new SubscriptionMap()
+    private proxy: ExtSearchFeaturesAPI
+
+    constructor(connection: Connection, private searchRegistry: FeatureProviderRegistry<{}, TransformQuerySignature>) {
+        this.subscriptions.add(this.registrations)
+
+        this.proxy = createProxyAndHandleRequests('searchFeatures', connection, this)
+    }
+
+    public $registerQueryTransformProvider(id: number): void {
+        this.registrations.add(
+            id,
+            this.searchRegistry.registerProvider(
+                {},
+                (query: string): Observable<string | null | undefined> => from(this.proxy.$transformQuery(id, query))
+            )
+        )
+    }
+
+    public $unregister(id: number): void {
+        this.registrations.remove(id)
+    }
+
+    public unsubscribe(): void {
+        this.subscriptions.unsubscribe()
+    }
+}

src/client/controller.ts

@@ -19,6 +19,7 @@ import { ClientConfiguration } from './api/configuration'
 import { ClientContext } from './api/context'
 import { ClientDocuments } from './api/documents'
 import { ClientLanguageFeatures } from './api/languageFeatures'
+import { SearchFeatures } from './api/search'
 import { ClientWindows } from './api/windows'
 import { applyContextUpdate, EMPTY_CONTEXT } from './context/context'
 import { EMPTY_ENVIRONMENT, Environment } from './environment'
@@ -268,6 +269,7 @@ export class Controller<X extends Extension, C extends ConfigurationCascade> imp
                 this.registries.textDocumentReferences
             )
         )
+        subscription.add(new SearchFeatures(client, this.registries.search))
         subscription.add(new ClientCommands(client, this.registries.commands))
     }
 

src/client/providers/search.ts

@@ -0,0 +1,33 @@
+import { Observable } from 'rxjs'
+import { switchMap } from 'rxjs/operators'
+import { FeatureProviderRegistry } from './registry'
+
+export type TransformQuerySignature = (query: string) => Observable<string | null | undefined>
+
+/** Provides transformed queries from the first search extension. */
+export class SearchTransformProviderRegistry extends FeatureProviderRegistry<{}, TransformQuerySignature> {
+    public transformQuery(query: string): Observable<string | null | undefined> {
+        return transformQuery(this.providers, query)
+    }
+}
+
+/**
+ * Returns an observable that emits the first provider's transformed query whenever any of the last-emitted set of providers emits
+ * a query.
+ *
+ * Most callers should use SearchTransformProviderRegistry's getHover method, which uses the registered search
+ * providers.
+ */
+export function transformQuery(
+    providers: Observable<TransformQuerySignature[]>,
+    query: string
+): Observable<string | null | undefined> {
+    return providers.pipe(
+        switchMap(providers => {
+            if (providers.length === 0) {
+                return [query]
+            }
+            return providers[0](query)
+        })
+    )
+}

src/client/registries.ts

@@ -7,6 +7,7 @@ import { ContributionRegistry } from './providers/contribution'
 import { TextDocumentDecorationProviderRegistry } from './providers/decoration'
 import { TextDocumentHoverProviderRegistry } from './providers/hover'
 import { TextDocumentLocationProviderRegistry, TextDocumentReferencesProviderRegistry } from './providers/location'
+import { SearchTransformProviderRegistry } from './providers/search'
 
 /**
  * Registries is a container for all provider registries.
@@ -25,4 +26,5 @@ export class Registries<X extends Extension, C extends ConfigurationCascade> {
     public readonly textDocumentTypeDefinition = new TextDocumentLocationProviderRegistry()
     public readonly textDocumentHover = new TextDocumentHoverProviderRegistry()
     public readonly textDocumentDecoration = new TextDocumentDecorationProviderRegistry()
+    public readonly search = new SearchTransformProviderRegistry()
 }

src/common/proxy.ts

@@ -18,6 +18,7 @@ export function createProxy(call: (name: string, args: any[]) => any): any {
             if (!target[name] && name[0] === '$') {
                 target[name] = (...args: any[]) => call(name, args)
             }
+
             return target[name]
         },
     })

src/extension/api/search.ts

@@ -0,0 +1,26 @@
+import { Unsubscribable } from 'rxjs'
+import { QueryTransformProvider } from 'sourcegraph'
+import { SearchFeaturesAPI } from 'src/client/api/search'
+import { ProviderMap } from './common'
+
+/** @internal */
+export interface ExtSearchFeaturesAPI {
+    $transformQuery: (id: number, query: string) => Promise<string | null | undefined>
+}
+
+/** @internal */
+export class ExtSearchFeatures implements ExtSearchFeaturesAPI {
+    private registrations = new ProviderMap<QueryTransformProvider>(id => this.proxy.$unregister(id))
+    constructor(private proxy: SearchFeaturesAPI) {}
+
+    public registerQueryTransformProvider(provider: QueryTransformProvider): Unsubscribable {
+        const { id, subscription } = this.registrations.add(provider)
+        this.proxy.$registerQueryTransformProvider(id)
+        return subscription
+    }
+
+    public $transformQuery(id: number, query: string): Promise<string | null | undefined> {
+        const provider = this.registrations.get<QueryTransformProvider>(id)
+        return Promise.resolve(provider.transformQuery(query))
+    }
+}

src/extension/extensionHost.ts

@@ -8,6 +8,7 @@ import { ExtConfiguration } from './api/configuration'
 import { ExtContext } from './api/context'
 import { ExtDocuments } from './api/documents'
 import { ExtLanguageFeatures } from './api/languageFeatures'
+import { ExtSearchFeatures } from './api/search'
 import { ExtWindows } from './api/windows'
 import { Location } from './types/location'
 import { Position } from './types/position'
@@ -82,6 +83,9 @@ function createExtensionHandle(initData: InitData, connection: Connection): type
     const languageFeatures = new ExtLanguageFeatures(proxy('languageFeatures'), documents)
     handleRequests(connection, 'languageFeatures', languageFeatures)
 
+    const searchFeatures = new ExtSearchFeatures(proxy('searchFeatures'))
+    handleRequests(connection, 'searchFeatures', searchFeatures)
+
     const commands = new ExtCommands(proxy('commands'))
     handleRequests(connection, 'commands', commands)
 
@@ -129,6 +133,10 @@ function createExtensionHandle(initData: InitData, connection: Connection): type
                 languageFeatures.registerReferenceProvider(selector, provider),
         },
 
+        search: {
+            registerQueryTransformProvider: provider => searchFeatures.registerQueryTransformProvider(provider),
+        },
+
         commands: {
             registerCommand: (command, callback) => commands.registerCommand({ command, callback }),
             executeCommand: (command, ...args) => commands.executeCommand(command, args),

src/sourcegraph.d.ts

@@ -717,6 +717,14 @@ declare module 'sourcegraph' {
         ): ProviderResult<Location[]>
     }
 
+    export interface QueryTransformProvider {
+        transformQuery(query: string): ProviderResult<string>
+    }
+
+    export namespace search {
+        export function registerQueryTransformProvider(provider: QueryTransformProvider): Unsubscribable
+    }
+
     export namespace languages {
         export function registerHoverProvider(selector: DocumentSelector, provider: HoverProvider): Unsubscribable