[FFL-2837] Expose precomputed configuration context

[btthomas]

Stack

1. Parse flags configuration wire format: #344
2. Expose the precomputed context <- you are here

This PR uses #344 as its base. Merge #344 first. Then retarget this PR to main.

Summary

This PR adds getPrecomputedContext(configuration) to @datadog/flagging-core.

The function returns a detached copy of the context from a valid precomputed configuration. It returns undefined when the configuration does not have a context-specific precomputed branch. The function does not change the configuration, OpenFeature, or provider state.

The function is available from these entry points:

• @datadog/flagging-core
• @datadog/flagging-core/configuration
• @datadog/flagging-core/precomputed
• @datadog/openfeature-browser
• @datadog/openfeature-browser/precomputed

The precomputed entry points remain free of Protobuf-ES modules.

Reason

The configuration wire and parsed configuration are opaque contracts. SDK users need a supported way to set the OpenFeature context for a context-specific precomputed configuration.

Without this function, each SDK must inspect internal configuration fields or implement the same accessor. A shared function keeps browser and React Native behavior consistent.

Behavior

• Preserve an explicit empty context.
• Preserve an explicit empty targeting key.
• Deep-copy nested objects, arrays, and dates.
• Return undefined for empty, rules-only, invalid-precomputed, and context-agnostic configurations.
• Return the precomputed context from a mixed valid configuration.

Validation

• 435 flagging-core tests passed.
• 156 browser tests passed.
• Flagging-core and browser type checks passed.
• Flagging-core and browser builds passed.
• Biome and Prettier checks passed.

[sameerank]

.setProvider is not awaitable so

Suggested change

	await OpenFeature.setProvider(provider)
	await OpenFeature.setProviderAndWait(provider)

or if we want to show an atomic registration of the context and initialization

Suggested change

	await OpenFeature.setProvider(provider)
	if (context !== undefined) {
	await OpenFeature.setProviderAndWait(provider, context)
	} else {
	await OpenFeature.setProviderAndWait(provider)
	}

[btthomas]

Thank you!
d0d2f51

[sameerank]

I see that applicationId is optional in the public type

openfeature-js-client/packages/browser/src/domain/configuration.ts

Line 15 in afe31a7

applicationId?: string

But DatadogProvider currently rejects its runtime configuration without it

openfeature-js-client/packages/browser/src/domain/configuration.ts

Lines 92 to 95 in afe31a7

	if (!initConfiguration.applicationId) {
	display.error('Application ID is not configured, no flagging data will be collected.')
	return
	}

Should we include applicationId in this example to match the current runtime behavior?

[btthomas]

Another PR coming soon for the optional/required bit.

Either way, fixed the README here: d0d2f51

[btthomas]

#355

[sameerank]

#344 has been rebased onto the latest main and force-pushed at 939da976. Could you rebase blake.thomas/FFL-2837/precomputed-context onto the updated sameerank/FFL-2835/configuration-from-string? (Never mind, I went ahead with the rebase) #346’s documented initialization flow depends on #353.

[leoromanovsky]

👍