Formed in 2009, the Archive Team (not to be confused with the archive.org Archive-It Team) is a rogue archivist collective dedicated to saving copies of rapidly dying or deleted websites for the sake of history and digital heritage. The group is 100% composed of volunteers and interested parties, and has expanded into a large amount of related projects for saving online and digital history.
Incorrect circularity detection #33191
Comments
|
here's another example from zone (source file function shallowObj(obj: {[k: string]: any} | undefined, depth: number): any {
if (!obj || !depth) return null;
const out: {[k: string]: any} = {};
for (const key in obj) {
if (obj.hasOwnProperty(key)) {
let value: any = obj[key];
switch (typeof value) {
case 'object':
const name = value && value.constructor && (<any>value.constructor).name;
value = name == (<any>Object).name ? shallowObj(value, depth - 1) : name;
break;
case 'function':
value = value.name || undefined;
break;
}
out[key] = value;
}
}
return out;
}Gives: |
|
Another example i've just come across, TypeScript version 2.8.3: function testFunction() {
let state: { value: number } | null = null;
for (let i = 0; i < 10; i++) {
const previousState = state;
// ^^^^^^^^^^^^^ error: 'previousState' implicitly has type 'any' because it does not have a type annotation and is referenced directly or indirectly in its own initializer.ts(7022)
state = null;
const value = i === 0 ? 0 : previousState?.value;
// ^^^^^ error: 'value' implicitly has type 'any' because it does not have a type annotation and is referenced directly or indirectly in its own initializer.ts(7022)
if (value !== undefined) {
state = { value: value + 1 }
}
}
console.log('Test Function:', state?.value);
}When putting in explicit type annotations, it produces a new error: function testFunction() {
let state: { value: number } | null = null;
for (let i = 0; i < 10; i++) {
const previousState: { value: number } | null = state;
state = null;
const value: number | undefined = i === 0 ? 0 : previousState?.value;
// Property 'value' does not exist on type 'never'.ts(2339): ^^^^^
if (value !== undefined) {
state = { value: value + 1 }
}
}
console.log('Test Function:', state?.value);
} |
|
Here's another case, but then with a interface Node {
next: Node | null;
}
function test(node: Node) {
let currentNode: Node | null = node;
while (currentNode !== null) {
const nextNode = currentNode.next;
// ~~~~~~~~ error TS7022: 'nextNode' implicitly has type 'any' because it does not have a type annotation
// and is referenced directly or indirectly in its own initializer.
currentNode = nextNode;
}
} |
|
BTW, using @JoostK's example, if you removes the asignation, error goes away... interface Node {
next: Node | null;
}
function test(node: Node) {
let currentNode: Node | null = node;
while (currentNode !== null) {
const nextNode = currentNode.next; // No error
// currentNode = nextNode; // Uncomment it, and error comes back
console.log(nextNode);
}
} |
Removing the assignment removes the circular nature of |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
TypeScript Version: 3.6.2
Search Terms:
Code
Expected behavior:
No error.
Actual behavior:
I'm really struggling to see where the circularity comes in. The type of
resultis shown as[number, number]in that branch, so I'd assume destructuring it would result in twonumbertypes.Removing the destructuring and using array accesses is equivalent but produces no error:
Playground Link: link
Related Issues:
The text was updated successfully, but these errors were encountered: