ClientSideBaseVisitor.fragmentsGraph is recomputed several times despite never changing

[vhfmag]

Which packages are impacted by your issue?

@graphql-codegen/visitor-plugin-common

Describe the bug

While profiling the graphql codegen step of one of my company's projects a sharp difference in build time after migrating from near-operation-file to client-preset, we identified that a disproportionate time is spent in these three lines:

const fragmentDependencyNames = new Set(
  fragmentNames.map(name => this.fragmentsGraph.dependenciesOf(name)).flatMap(item => item)
);

You can see that in the flamegraph below, where all of the green traces on the bottom are time spent on those lines — I added a couple arrows to help visualize which trace I mean, but it's all traces of the same color, not just these 4

The reason why that line is so expensive is that this.fragmentsGraph is an expensive getter. In addition to that, it only depends on this._fragments and this._extractFragments(). The this._extractFragments only depends on this._fragments and itself (it's recursive), and this._fragments isn't reassigned or modified (which we verified by changing its declaration to private readonly _fragments: ReadonlyMap<string, LoadedFragment>).

With that in mind, we converted fragmentsGraph from a getter to a regular property, and our build time went from ~130 seconds to ~50s. I'm opening this issue to share our findings and share a PR proposing a related performance improvement.

Your Example Website or App

N/A

Steps to Reproduce the Bug or Issue

1. Run codegen on a mid-sized project using client-preset and measure the build time
2. Make the change to only compute fragmentsGraph once per ClientSideBaseVisitor instance
3. Run codegen again and compare the build time

Expected behavior

client-preset should be faster by avoiding costly recomputations of unchanged data

Screenshots or Videos

No response

Platform

• OS: macOS
• NodeJS: 18.18.2
• graphql version: 16.2.0
• @graphql-codegen/client-preset version(s): 4.2.6
• @graphql-codegen/visitor-plugin-common version(s): 2.13.1

Codegen Config File

No response

Additional context

No response

[vhfmag]

Hi @n1ru4l! I see you merged #10019 (thanks!), but there hasn't been a version release yet. I'm wondering what the usual release process is

[n1ru4l]

@vhfmag Releasing it right now 😇 #10010