implement import action

Author: yukukotani

package-lock.json

@@ -21,6 +21,7 @@
     "typescript": "^4.3.5"
   },
   "devDependencies": {
+    "@types/node": "^16.7.10",
     "@ubie/prettier-config": "^0.1.0",
     "prettier": "^2.3.2"
   }

package.json

@@ -1,7 +1,20 @@
-import TsServerLibrary from 'typescript/lib/tsserverlibrary';
+import TsServerLibrary, { CodeFixAction, ScriptElementKind } from 'typescript/lib/tsserverlibrary';
+import * as path from 'path';
+
+declare global {
+  namespace ts {
+    interface CompletionEntryData {
+      modulePath?: string;
+    }
+  }
+}
+
+function stripExt(filePath: string) {
+  return filePath.slice(0, filePath.lastIndexOf('.'));
+}
 
 function init({ typescript: ts }: { typescript: typeof TsServerLibrary }) {
-  function create(info: ts.server.PluginCreateInfo) {
+  function create(info: TsServerLibrary.server.PluginCreateInfo) {
     const log = (...params: unknown[]) => {
       const text = params.map((p) => (p ? JSON.stringify(p) : p)).join(' ');
       info.project.projectService.logger.info(`[namespace-import] ${text}`);
@@ -23,11 +36,53 @@ function init({ typescript: ts }: { typescript: typeof TsServerLibrary }) {
         source: '/Users/yukukotani/ghq/github.com/ubie-inc/yukustory/packages/client/src/TestService.ts',
         sortText: 'TestService',
         hasAction: true,
+        isImportStatementCompletion: true,
+        data: {
+          exportName: 'TestService',
+          modulePath: '/Users/yukukotani/ghq/github.com/ubie-inc/yukustory/packages/client/src/TestService.ts',
+        },
       };
       original.entries.push(entry);
 
       return original;
     };
+
+    const getCompletionEntryDetails = info.languageService.getCompletionEntryDetails;
+    info.languageService.getCompletionEntryDetails = (fileName, position, name, options, source, preferences, data) => {
+      log('getCompletionEntryDetails', { fileName, position, name, options, source });
+      if (name === 'TestService' && data?.modulePath) {
+        const importPath = path.relative(path.dirname(fileName), data.modulePath);
+        const text = `import * as ${name} from "${stripExt(importPath)}";\n`;
+        const action: CodeFixAction = {
+          fixName: 'namespace-import',
+          description: text,
+          changes: [
+            {
+              fileName: fileName,
+              textChanges: [
+                {
+                  span: {
+                    start: 0,
+                    length: 0,
+                  },
+                  newText: text,
+                },
+              ],
+            },
+          ],
+          commands: [],
+        };
+        return {
+          name: name,
+          kind: ScriptElementKind.alias,
+          kindModifiers: '',
+          displayParts: [],
+          codeActions: [action],
+        };
+      }
+
+      return getCompletionEntryDetails(fileName, position, name, options, source, preferences, data);
+    };
   }
 
   return { create };