feat(tracing): Add transaction.setContext method

[AbhiPrasad]

This is needed for the OpenTelemetry Span Processor. Same behaviour as scope.setContext here:

sentry-javascript/packages/core/src/scope.ts

Lines 257 to 270 in 351be06

	/**
	* @inheritDoc
	*/
	public setContext(key: string, context: Context | null): this {
	if (context === null) {
	// eslint-disable-next-line @typescript-eslint/no-dynamic-delete
	delete this._contexts[key];
	} else {
	this._contexts = { ...this._contexts, [key]: context };
	}
	this._notifyScopeListeners();
	return this;
	}

One thing to note, we don't want users to override trace context, so we set that here.

[mydea]

l: Is it important to make this a new object every time? Or could we just do:

this._contexts[key] = context;

? To avoid re-creating objects when we don't really need to do so.

[AbhiPrasad]

I copied this from

sentry-javascript/packages/core/src/scope.ts

Lines 257 to 270 in 351be06

	/**
	* @inheritDoc
	*/
	public setContext(key: string, context: Context | null): this {
	if (context === null) {
	// eslint-disable-next-line @typescript-eslint/no-dynamic-delete
	delete this._contexts[key];
	} else {
	this._contexts = { ...this._contexts, [key]: context };
	}
	this._notifyScopeListeners();
	return this;
	}

I agree though, will change. Perhaps we can update the scope file as well then?

[mydea]

I think that makes sense as well 👍

[AbhiPrasad]

536dca6

[github-actions]

size-limit report 📦

Path	Size
@sentry/browser - ES5 CDN Bundle (gzipped + minified)	19.5 KB (0%)
@sentry/browser - ES5 CDN Bundle (minified)	60.37 KB (0%)
@sentry/browser - ES6 CDN Bundle (gzipped + minified)	18.15 KB (+0.02% 🔺)
@sentry/browser - ES6 CDN Bundle (minified)	53.71 KB (0%)
@sentry/browser - Webpack (gzipped + minified)	19.89 KB (0%)
@sentry/browser - Webpack (minified)	65.12 KB (0%)
@sentry/react - Webpack (gzipped + minified)	19.92 KB (0%)
@sentry/nextjs Client - Webpack (gzipped + minified)	45.9 KB (+0.05% 🔺)
@sentry/browser + @sentry/tracing - ES5 CDN Bundle (gzipped + minified)	26.32 KB (+0.11% 🔺)
@sentry/browser + @sentry/tracing - ES6 CDN Bundle (gzipped + minified)	24.73 KB (+0.12% 🔺)

[mydea]

LGTM! When this is merged I can adjust the SpanProcessor to use this.