Cached result is not instantly returned when fetchPolicy is set to "cache-and-network"

[MCYouks]

Describe the bug
When settings the query options with { fetchPolicy: "cache-and-network" }, the cached result is not instantly returned.

Instead, it waits until the data is fetched from the server to return the result.

To Reproduce
Steps to reproduce the behavior:

1. Setup useQuery with the following options { fetchPolicy: "cache-and-network" }
2. Setup 2 query variables: variables1 and variables2
3. Execute the query with variables1, then variables2, then variables1 again — e.g. const { result } = useQuery(query, variable1, { fetchPolicy: "cache-and-network" })
4. On the second time you query with variables1, the change in result won't be instantaneous. Instead, it will wait for a few seconds before updating.

Expected behavior
The cached result should be returned instantly.

Versions
vue: "^3.2.16"
@vue/apollo-composable: "^4.0.0-alpha.16"
@apollo/client: "^3.5.8"

[Kakahn]

We have identified the same issue.

In the meantime, for this to be corrected, it would seem that if we add

notifyOnNetworkStatusChange: true,

at the useQuery level it works. But impossible to put it at the level of the config of apollo in defaultOptions.

Wait and see :)

[productdevbook]

some problem

[tafelnl]

notifyOnNetworkStatusChange: true does fix it for fetching the query the first time. But if your component refetches the query (because of reactive variables changing or whatever), it will have the same issue again. So it's a workaround for some simple use cases, but definitely not for all use cases (and it's pretty common to use reactive variables in queries).

[ishitatsuyuki]

If you're affected by this, could you please try #1388? You can setup linking manually or put "@vue/apollo-composable": "npm:@ishitatsuyuki/apollo-composable@4.0.0-alpha.19.usequery-stale" in your package.json. Let me know if it fix (or does not fix) your issues!

[xvaara]

@ishitatsuyuki fixes the issue for me.

[tafelnl]

Heads up: there's now a release that ships the fix of @ishitatsuyuki https://github.com/vuejs/apollo/releases/tag/v4.0.0-beta.1

[Narretz]

This is fixed in vue-apollo 4.x, but the same logic exists in vue-apollo 3.x, see:

apollo/packages/vue-apollo/src/smart-query.js

Lines 115 to 123 in fdc6fb8

	if (this.options.fetchPolicy !== 'no-cache' || this.options.notifyOnNetworkStatusChange) {
	const currentResult = this.retrieveCurrentResult()
	if (this.options.notifyOnNetworkStatusChange ||
	// Initial call of next result when it's not loading (for Apollo Client 3)
	(this.observer.getCurrentResult && !currentResult.loading)) {
	this.nextResult(currentResult)
	}
	}

Removing the code also fixes the issue, but I found that at least in 3.x, the code does something.

Consider the following:

• parent component executes query against network, and then renders child component
• child component executes a query against cache-first

with the above code, the child component has the cached data before the component tries to render the template. Without the code, it doesn't (and you have to use v-if etc. to wait for the data)

This brings me to the point that vue-apollo is still not well tested.

• the pull request was merged without an accompanying test case. A bug fix should always have a test case
• the code that was removed apparentely wasn't covered by a test case either (but this may be because it was copied from the 3.x branch).
• a common use case such as cache-and-network apparently wasn't tested either

As long as the testing strategy is subpar, errors like this will pop up again and again.

[viljark]

I ended up patching the @vue/apollo-option directly inside vue-apollo-option.esm.js for now, I'm not 100% sure of the logic, but it solved the issue for us with "cache-and-network" not returning any cached results. Also network-only and cache-only seemed to work as expected.

diff --git a/node_modules/@vue/apollo-option/dist/vue-apollo-option.esm.js b/node_modules/@vue/apollo-option/dist/vue-apollo-option.esm.js
index e5a7f2f..efb1d95 100644
--- a/node_modules/@vue/apollo-option/dist/vue-apollo-option.esm.js
+++ b/node_modules/@vue/apollo-option/dist/vue-apollo-option.esm.js
@@ -783,7 +783,8 @@ var SmartQuery = /*#__PURE__*/function (_SmartApollo) {
         var currentResult = this.retrieveCurrentResult();
         if (this.options.notifyOnNetworkStatusChange ||
         // Initial call of next result when it's not loading (for Apollo Client 3)
-        this.observer.getCurrentResult && !currentResult.loading) {
+          (this.observer.getCurrentResult && this.options.fetchPolicy !== 'network-only') ||
+          (this.observer.getCurrentResult && this.options.fetchPolicy === 'network-only' && !currentResult.loading)) {
           this.nextResult(currentResult);
         }
       }