From 1d2c9d8e70a1883a02aa41020c23191b0ffd00a6 Mon Sep 17 00:00:00 2001
From: Sergei Zharinov <zharinov@users.noreply.github.com>
Date: Tue, 11 Jan 2022 10:36:26 +0300
Subject: [PATCH] refactor(util/lazy): Strict null check (#13455)
* refactor(util/lazy): Strict null check
* Reimplement without `never` type cast
* Revert tsconfig.json
* Fix
---
lib/util/lazy.ts | 44 ++++++++++++++++++++++++++++++--------------
tsconfig.strict.json | 2 ++
2 files changed, 32 insertions(+), 14 deletions(-)
diff --git a/lib/util/lazy.ts b/lib/util/lazy.ts
index b998e31527..079413b359 100644
--- a/lib/util/lazy.ts
+++ b/lib/util/lazy.ts
@@ -1,27 +1,43 @@
+interface ValueResult<T> {
+ type: 'success';
+ value: T;
+}
+
+interface ErrorResult {
+ type: 'error';
+ err: Error;
+}
+
export class Lazy<T> {
- private _didRun = false;
- private _value?: T;
- private _error: Error | undefined;
+ private _result?: ValueResult<T> | ErrorResult;
constructor(private readonly executor: () => T) {}
hasValue(): boolean {
- return this._didRun;
+ return !!this._result;
}
getValue(): T {
- if (!this._didRun) {
- try {
- this._value = this.executor();
- } catch (err) {
- this._error = err;
- } finally {
- this._didRun = true;
+ const result = this._result;
+ if (result) {
+ if (result.type === 'success') {
+ return result.value;
}
+
+ throw result.err;
}
- if (this._error) {
- throw this._error;
+
+ return this.realizeValue();
+ }
+
+ private realizeValue(): T {
+ try {
+ const value = this.executor();
+ this._result = { type: 'success', value };
+ return value;
+ } catch (err) {
+ this._result = { type: 'error', err };
+ throw err;
}
- return this._value;
}
}
diff --git a/tsconfig.strict.json b/tsconfig.strict.json
index f985628d41..76e486bf5b 100644
--- a/tsconfig.strict.json
+++ b/tsconfig.strict.json
@@ -52,6 +52,8 @@
"lib/util/host-rules.ts",
"lib/util/html.ts",
"lib/util/http/**/.ts",
+ "lib/util/lazy.ts",
+ "lib/util/lazy.spec.ts",
"lib/util/index.ts",
"lib/util/json-writer/code-format.ts",
"lib/util/json-writer/editor-config.ts",
--
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