From 1bea9c106c7efc22ba5c73f60d1c7ca67f32f687 Mon Sep 17 00:00:00 2001
From: Meinhardt Klaus <klaus.meinhardt@corpuls.com>
Date: Sun, 6 Dec 2020 18:29:51 +0100
Subject: [PATCH] new rule: initialize-static-property

Fixes: #557
---
 baselines/packages/mimir/api/packlist.txt     |  3 ++
 .../src/rules/initialize-static-property.d.ts |  4 +++
 packages/mimir/recommended.yaml               |  1 +
 .../src/rules/initialize-static-property.ts   | 28 +++++++++++++++++++
 4 files changed, 36 insertions(+)
 create mode 100644 baselines/packages/mimir/api/src/rules/initialize-static-property.d.ts
 create mode 100644 packages/mimir/src/rules/initialize-static-property.ts

diff --git a/baselines/packages/mimir/api/packlist.txt b/baselines/packages/mimir/api/packlist.txt
index aa0694829..4834fe47f 100644
--- a/baselines/packages/mimir/api/packlist.txt
+++ b/baselines/packages/mimir/api/packlist.txt
@@ -28,6 +28,9 @@ src/rules/delete-only-optional-property.js.map
 src/rules/generator-require-yield.d.ts
 src/rules/generator-require-yield.js
 src/rules/generator-require-yield.js.map
+src/rules/initialize-static-property.d.ts
+src/rules/initialize-static-property.js
+src/rules/initialize-static-property.js.map
 src/rules/new-parens.d.ts
 src/rules/new-parens.js
 src/rules/new-parens.js.map
diff --git a/baselines/packages/mimir/api/src/rules/initialize-static-property.d.ts b/baselines/packages/mimir/api/src/rules/initialize-static-property.d.ts
new file mode 100644
index 000000000..ebd9e13b8
--- /dev/null
+++ b/baselines/packages/mimir/api/src/rules/initialize-static-property.d.ts
@@ -0,0 +1,4 @@
+import { AbstractRule } from '@fimbul/ymir';
+export declare class Rule extends AbstractRule {
+    apply(): void;
+}
diff --git a/packages/mimir/recommended.yaml b/packages/mimir/recommended.yaml
index 90664329d..40e85ec98 100644
--- a/packages/mimir/recommended.yaml
+++ b/packages/mimir/recommended.yaml
@@ -6,6 +6,7 @@ rules:
   ban-dom-globals: error
   delete-only-optional-property: error
   generator-require-yield: error
+  initialize-static-property: error
   new-parens: error
   no-case-declaration: error
   no-debugger: error
diff --git a/packages/mimir/src/rules/initialize-static-property.ts b/packages/mimir/src/rules/initialize-static-property.ts
new file mode 100644
index 000000000..a32f355cf
--- /dev/null
+++ b/packages/mimir/src/rules/initialize-static-property.ts
@@ -0,0 +1,28 @@
+import { AbstractRule, excludeDeclarationFiles } from '@fimbul/ymir';
+import * as ts from 'typescript';
+import { WrappedAst, getWrappedNodeAtPosition, isPropertyDeclaration, isStatementInAmbientContext, hasModifier } from 'tsutils';
+
+@excludeDeclarationFiles
+export class Rule extends AbstractRule {
+    public apply() {
+        let wrappedAst: WrappedAst | undefined;
+        const {text} = this.sourceFile;
+        const re = /\bstatic\b/g;
+
+        for (let match = re.exec(text); match !== null; match = re.exec(text)) {
+            const {node} = getWrappedNodeAtPosition(wrappedAst || (wrappedAst = this.context.getWrappedAst()), match.index)!;
+            if (node.kind !== ts.SyntaxKind.StaticKeyword)
+                continue;
+            const member = node.parent!;
+            if (
+                isPropertyDeclaration(member) &&
+                member.initializer === undefined &&
+                member.questionToken === undefined &&
+                // TODO move to tsutils as isAmbientPropertyDeclaration
+                !hasModifier(member.modifiers, ts.SyntaxKind.DeclareKeyword) &&
+                !(member.parent!.kind === ts.SyntaxKind.ClassDeclaration && isStatementInAmbientContext(member.parent!))
+            )
+                this.addFindingAtNode(member.name, "Non-optional 'static' property must be initialized.");
+        }
+    }
+}