feat: Import Statement Completions (#291)

https://devblogs.microsoft.com/typescript/announcing-typescript-4-3/#import-statement-completions

src/server/features/completionItemProvider.ts

@@ -49,7 +49,7 @@ class ApplyCompletionCodeActionCommand implements CommandItem {
 
 export default class TypeScriptCompletionItemProvider implements CompletionItemProvider {
 
-  public static readonly triggerCharacters = ['.', '"', '\'', '`', '/', '@', '<', '#']
+  public static readonly triggerCharacters = ['.', '"', '\'', '`', '/', '@', '<', '#', ' ']
   private completeOption: SuggestOptions
 
   constructor(
@@ -148,7 +148,7 @@ export default class TypeScriptCompletionItemProvider implements CompletionItemP
             dotAccessorContext = { range, text }
           }
         }
-        isIncomplete = (response as any).metadata && (response as any).metadata.isIncomplete
+        isIncomplete = !!response.body.isIncomplete || (response as any).metadata && (response as any).metadata.isIncomplete
         entries = response.body.entries
       } catch (e) {
         if (e.message == 'No content available.') {
@@ -194,6 +194,8 @@ export default class TypeScriptCompletionItemProvider implements CompletionItemP
 
       case '#': // Workaround for https://github.com/microsoft/TypeScript/issues/36367
         return this.client.apiVersion.lt(API.v381) ? undefined : '#'
+      case ' ':
+        return this.client.apiVersion.gte(API.v430) ? ' ' : undefined
 
       case '.':
       case '"':
@@ -338,6 +340,13 @@ export default class TypeScriptCompletionItemProvider implements CompletionItemP
       }
     }
 
+    if (triggerCharacter === ' ') {
+      if (!this.completeOption.importStatementSuggestions || !this.client.apiVersion.lt(API.v430)) {
+        return false
+      }
+      return pre === 'import ';
+    }
+
     return true
   }
 

src/server/features/fileConfigurationManager.ts

@@ -37,6 +37,9 @@ export interface SuggestOptions {
   readonly completeFunctionCalls: boolean
   readonly autoImports: boolean
   readonly includeAutomaticOptionalChainCompletions: boolean
+  readonly importStatementSuggestions: boolean
+  readonly includeCompletionsForImportStatements: boolean
+  readonly includeCompletionsWithSnippetText: boolean
 }
 
 export default class FileConfigurationManager {
@@ -156,6 +159,9 @@ export default class FileConfigurationManager {
       paths: config.get<boolean>('paths', true),
       completeFunctionCalls: config.get<boolean>('completeFunctionCalls', true),
       autoImports: config.get<boolean>('autoImports', true),
+      importStatementSuggestions: config.get<boolean>('importStatements', true),
+      includeCompletionsForImportStatements: config.get<boolean>('includeCompletionsForImportStatements', true),
+      includeCompletionsWithSnippetText: config.get<boolean>('includeCompletionsWithSnippetText', true),
       includeAutomaticOptionalChainCompletions: config.get<boolean>('includeAutomaticOptionalChainCompletions', true)
     }
   }
@@ -173,6 +179,8 @@ export default class FileConfigurationManager {
       allowTextChangesInNewFiles: uri.startsWith('file:'),
       allowRenameOfImportPath: true,
       providePrefixAndSuffixTextForRename: config.get<boolean>('renameShorthandProperties', true) === false ? false : config.get<boolean>('useAliasesForRenames', true),
+      includeCompletionsForImportStatements: this.getCompleteOptions(language).includeCompletionsForImportStatements,
+      includeCompletionsWithSnippetText: this.getCompleteOptions(language).includeCompletionsWithSnippetText,
     }
     return preferences
   }
@@ -190,7 +198,7 @@ export default class FileConfigurationManager {
 
 type ModuleImportType = 'relative' | 'non-relative' | 'auto'
 
-function getImportModuleSpecifier(config): ModuleImportType {
+function getImportModuleSpecifier(config: WorkspaceConfiguration): ModuleImportType {
   let val = config.get('importModuleSpecifier')
   switch (val) {
     case 'relative':

src/server/utils/api.ts

@@ -39,7 +39,9 @@ export default class API {
   public static readonly v381 = API.fromSimpleString('3.8.1')
   public static readonly v390 = API.fromSimpleString('3.9.0')
   public static readonly v400 = API.fromSimpleString('4.0.0')
-  public static readonly v401 = API.fromSimpleString('4.0.1');
+  public static readonly v401 = API.fromSimpleString('4.0.1')
+  public static readonly v420 = API.fromSimpleString('4.2.0')
+  public static readonly v430 = API.fromSimpleString('4.3.0')
 
   public static fromVersionString(versionString: string): API {
     let version = semver.valid(versionString)

src/server/utils/completionItem.ts

@@ -37,7 +37,7 @@ export function convertCompletionEntry(
   if (tsEntry.isRecommended) {
     preselect = true
   }
-  if (tsEntry.source) {
+  if (tsEntry.source && tsEntry.hasAction) {
     // De-prioritze auto-imports https://github.com/Microsoft/vscode/issues/40311
     sortText = '\uffff' + sortText
   } else {
@@ -53,13 +53,18 @@ export function convertCompletionEntry(
   let insertText = tsEntry.insertText
   let commitCharacters = getCommitCharacters(tsEntry, context)
 
+  if (tsEntry.isImportStatementCompletion) {
+    insertText = label
+    insertTextFormat = InsertTextFormat.Snippet
+  }
+
   let textEdit: TextEdit | null = null
   if (tsEntry.replacementSpan) {
     let { start, end } = tsEntry.replacementSpan
     if (start.line == end.line) {
       textEdit = {
         range: Range.create(start.line - 1, start.offset - 1, end.line - 1, end.offset - 1),
-        newText: insertText || label
+        newText: tsEntry.insertText || label
       }
     }
   }