editor: add code completion snippets

Author: x1unix

README.md

@@ -44,7 +44,8 @@ Use `-help` to get information about command params
 ### Third-party credits
 
 * Default playground run server provided by [play.golang.org](https://play.golang.org)
-* Snippets for templates and tutorials provided by [gobyexample.com](https://gobyexample.com/) 
+* Code for templates and tutorials provided by [gobyexample.com](https://gobyexample.com/)
+* Code completion snippets were inspired by [tj/vscode-snippets](https://github.com/tj/vscode-snippets/blob/master/go.json)
 
 
 ## Contributors

web/src/editor/provider.ts

@@ -1,5 +1,6 @@
 import * as monaco from 'monaco-editor';
 import {IAPIClient} from '../services/api';
+import snippets from './snippets'
 
 // Import aliases
 type CompletionList = monaco.languages.CompletionList;
@@ -53,10 +54,11 @@ class GoCompletionItemProvider implements monaco.languages.CompletionItemProvide
 
         try {
             const resp = await this.client.getSuggestions(query);
-            return Promise.resolve(resp);
+            resp.suggestions = resp.suggestions ? snippets.concat(resp.suggestions) : snippets;
+            return resp;
         } catch (err) {
             console.error(`Failed to get code completion from server: ${err.message}`);
-            return Promise.resolve({suggestions: []});
+            return {suggestions: snippets};
         }
     }
 }

web/src/editor/snippets.ts

@@ -0,0 +1,128 @@
+import * as monaco from 'monaco-editor';
+
+/* eslint-disable no-template-curly-in-string */
+
+// Import aliases
+type CompletionList = monaco.languages.CompletionList;
+type CompletionContext = monaco.languages.CompletionContext;
+type ITextModel = monaco.editor.ITextModel;
+type Position = monaco.Position;
+
+/**
+ * List of snippets for editor
+ */
+const snippets = [
+    {
+        label: 'iferr',
+        insertText: [
+            'if err != nil {',
+            '\treturn ${1:nil, err}',
+            '}'
+        ].join('\n'),
+        documentation: 'Return error if err != nil'
+    },
+    {
+        label: 'switch',
+        insertText: [
+            "switch ${1:expression} {",
+            "\tcase ${2:match}:",
+            "\t\t$0",
+            "\tdefault:",
+            "\t\t// TODO: implement",
+            "}",
+        ].join('\n'),
+        documentation: 'Insert switch statement'
+    },
+    {
+        label: 'go',
+        insertText: [
+            "go func(){",
+            "\t$0",
+            "}()"
+        ].join('\n'),
+        documentation: 'Call goroutine'
+    },
+    {
+        label: 'append',
+        insertText: "$1 = append($1, $0)",
+        documentation: 'Append to slice'
+    },
+    {
+        label: 'typestruct',
+        insertText: [
+            "type ${1:name} struct {",
+            "\t$0",
+            "}"
+        ].join('\n'),
+        documentation: 'Declare a struct'
+    },
+    {
+        label: 'typeinterface',
+        insertText: [
+            "type ${1:name} interface {",
+            "\t$0",
+            "}"
+        ].join('\n'),
+        documentation: 'Declare a struct'
+    },
+    {
+        label: 'fmtprintf',
+        insertText: 'fmt.Printf("${1:format}\n", $0)',
+        documentation: 'fmt.Printf() shorthand'
+    },
+    {
+        label: 'fmtprintln',
+        insertText: 'fmt.Println(${0:message})',
+        documentation: 'fmt.Println() shorthand'
+    },
+    {
+        label: 'returnnil',
+        insertText: 'return nil',
+        documentation: 'return nil'
+    },
+    {
+        label: 'timenow',
+        insertText: '${0:t} := time.Now()',
+        documentation: 'time.Now() shorthand'
+    },
+    {
+        label: 'makeslice',
+        insertText: '${0:items} := make([]${1:string}, ${2:0}, ${3:0})',
+        documentation: 'Make a new slice'
+    },
+    {
+        label: 'slice',
+        insertText: '${1:items} := []${2:string}{${0}}',
+        documentation: 'Declare slice'
+    },
+    {
+        label: 'map',
+        insertText: 'map[${1:string}]${0:value}',
+        documentation: 'Insert map type'
+    },
+    {
+        label: 'func',
+        insertText: [
+            "func ${1:functionName}(${3:param}) $4 {",
+            "  $0",
+            "}"
+        ].join('\n'),
+        documentation: 'Insert a function'
+    },
+    {
+        label: 'for',
+        insertText: [
+            "for _, ${1:v} := range ${2:value} {",
+            "  $0",
+            "}"
+        ].join('\n'),
+        documentation: 'Insert a for range statement'
+    },
+
+].map(s => ({
+    kind: monaco.languages.CompletionItemKind.Snippet,
+    insertTextRules: monaco.languages.CompletionItemInsertTextRule.InsertAsSnippet,
+    ...s,
+}));
+
+export default snippets as monaco.languages.CompletionItem[];