Package suggestion for _test.go (#1220)

* Package suggestion for _test.go

* Add semicolon

* Package suggestion for _test.go

* Add semicolon

* Consider package suggestion with dir contains main.go

* Always resolve

* Guest package name when the directory name consist of mutiple words

* Fix typo

* Guess all dirname

* Use capital

* Use stat instead of readdir

* Fallback proposedPkgName when main.go not found

* Moved guessPkg to utils so its reusable

src/goSuggest.ts

@@ -7,12 +7,12 @@
 
 import vscode = require('vscode');
 import cp = require('child_process');
-import { dirname, basename } from 'path';
-import { getBinPath, parameters, parseFilePrelude, isPositionInString, goKeywords, getToolsEnvVars, timeout } from './util';
+import { getBinPath, parameters, parseFilePrelude, isPositionInString, goKeywords, getToolsEnvVars, timeout, guessPackageNameFromFile } from './util';
 import { promptForMissingTool } from './goInstallTools';
 import { getTextEditForAddImport } from './goImport';
 import { getImportablePackages } from './goPackages';
 
+
 function vscodeKindFromGoCodeClass(kind: string): vscode.CompletionItemKind {
 	switch (kind) {
 		case 'const':
@@ -148,21 +148,6 @@ export class GoCompletionItemProvider implements vscode.CompletionItemProvider {
 					let suggestions = [];
 					let suggestionSet = new Set<string>();
 
-					// 'Smart Snippet' for package clause
-					// TODO: Factor this out into a general mechanism
-					if (!inputText.match(/package\s+(\w+)/)) {
-						let defaultPackageName =
-							basename(filename) === 'main.go'
-								? 'main'
-								: basename(dirname(filename));
-						if (defaultPackageName.match(/[a-zA-Z_]\w*/)) {
-							let packageItem = new vscode.CompletionItem('package ' + defaultPackageName);
-							packageItem.kind = vscode.CompletionItemKind.Snippet;
-							packageItem.insertText = 'package ' + defaultPackageName + '\r\n\r\n';
-							suggestions.push(packageItem);
-						}
-
-					}
 					if (results[1]) {
 						for (let suggest of results[1]) {
 							if (inString && suggest.class !== 'import') continue;
@@ -204,6 +189,18 @@ export class GoCompletionItemProvider implements vscode.CompletionItemProvider {
 					let importablePkgs = includeUnimportedPkgs ? this.getMatchingPackages(currentWord, suggestionSet) : [];
 					suggestions = suggestions.concat(importablePkgs);
 
+					// 'Smart Snippet' for package clause
+					// TODO: Factor this out into a general mechanism
+					if (!inputText.match(/package\s+(\w+)/)) {
+						return guessPackageNameFromFile(filename).then(pkgName => {
+							let packageItem = new vscode.CompletionItem('package ' + pkgName);
+							packageItem.kind = vscode.CompletionItemKind.Snippet;
+							packageItem.insertText = 'package ' + pkgName + '\r\n\r\n';
+							suggestions.push(packageItem);
+							resolve(suggestions);
+						}, () => resolve(suggestions));
+					}
+
 					resolve(suggestions);
 				} catch (e) {
 					reject(e);

src/util.ts

@@ -428,3 +428,55 @@ export function getImportPath(text: string): string {
 
 	return '';
 }
+
+// TODO: Add unit tests for the below
+
+/**
+ * Guess the package name based on parent directory name of the given file
+ *
+ * Cases:
+ * - dir 'go-i18n' -> 'i18n'
+ * - dir 'go-spew' -> 'spew'
+ * - dir 'kingpin' -> 'kingpin'
+ * - dir 'go-expand-tilde' -> 'tilde'
+ * - dir 'gax-go' -> 'gax'
+ * - dir 'go-difflib' -> 'difflib'
+ * - dir 'jwt-go' -> 'jwt'
+ * - dir 'go-radix' -> 'radix'
+ *
+ * @param {string} filePath.
+ */
+export function guessPackageNameFromFile(filePath): Promise<string> {
+	return new Promise((resolve, reject) => {
+
+		const goFilename = path.basename(filePath);
+		if (goFilename === 'main.go') {
+			return resolve('main');
+		}
+
+		const directoryPath = path.dirname(filePath);
+		let segments = directoryPath.split(/[\.-]/);
+		segments = segments.filter(val => val !== 'go');
+
+		if (segments.length === 0 || !/[a-zA-Z_]\w*/.test(segments[segments.length - 1])) {
+			return reject();
+		}
+
+		const proposedPkgName = segments[segments.length - 1];
+
+		if (goFilename.endsWith('internal_test.go')) {
+			return resolve(proposedPkgName);
+		}
+
+		if (goFilename.endsWith('_test.go')) {
+			return resolve(proposedPkgName + '_test');
+		}
+
+		fs.stat(path.join(directoryPath, 'main.go'), (err, stats) => {
+			if (stats && stats.isFile()) {
+				return resolve('main');
+			}
+			return resolve(proposedPkgName);
+		});
+	});
+}