detectRouteCollision() — astro Function Reference

Architecture documentation for the detectRouteCollision() function in create.ts from the astro codebase.

Function typescript CoreAstro RoutingSystem calls 1 called by 1

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CoreAstro→ RoutingSystem→ detectRouteCollision() — astro Function Reference

Dependency Diagram

graph TD
  6d3eab18_f149_cd0f_b9bf_e3324684390e["detectRouteCollision()"]
  a7eed989_9f2b_5163_ecdf_85920a8b973f["create.ts"]
  6d3eab18_f149_cd0f_b9bf_e3324684390e -->|defined in| a7eed989_9f2b_5163_ecdf_85920a8b973f
  980f5a1b_85ee_0217_7a04_888abfb8f70f["createRoutesList()"]
  980f5a1b_85ee_0217_7a04_888abfb8f70f -->|calls| 6d3eab18_f149_cd0f_b9bf_e3324684390e
  b81576c5_5ca8_7f92_fc59_7489816844e2["isSemanticallyEqualSegment()"]
  6d3eab18_f149_cd0f_b9bf_e3324684390e -->|calls| b81576c5_5ca8_7f92_fc59_7489816844e2
  style 6d3eab18_f149_cd0f_b9bf_e3324684390e fill:#6366f1,stroke:#818cf8,color:#fff

Relationship Graph

Source Code

packages/astro/src/core/routing/manifest/create.ts lines 425–482

function detectRouteCollision(a: RouteData, b: RouteData, _config: AstroConfig, logger: Logger) {
	if (a.type === 'fallback' || b.type === 'fallback') {
		// If either route is a fallback route, they don't collide.
		// Fallbacks are always added below other routes exactly to avoid collisions.
		return;
	}

	if (
		a.route === b.route &&
		a.segments.every(isStaticSegment) &&
		b.segments.every(isStaticSegment)
	) {
		// If both routes are the same and completely static they are guaranteed to collide
		// such that one of them will never be matched.
		logger.warn(
			'router',
			`The route "${a.route}" is defined in both "${a.component}" and "${b.component}". A static route cannot be defined more than once.`,
		);
		logger.warn(
			'router',
			'A collision will result in an hard error in following versions of Astro.',
		);
		return;
	}

	if (a.prerender || b.prerender) {
		// If either route is prerendered, it is impossible to know if they collide
		// at this stage because it depends on the parameters returned by `getStaticPaths`.
		return;
	}

	if (a.segments.length !== b.segments.length) {
		// If the routes have different number of segments, they cannot perfectly overlap
		// each other, so a collision is either not guaranteed or may be intentional.
		return;
	}

	// Routes have the same number of segments, can use either.
	const segmentCount = a.segments.length;

	for (let index = 0; index < segmentCount; index++) {
		const segmentA = a.segments[index];
		const segmentB = b.segments[index];

		if (!isSemanticallyEqualSegment(segmentA, segmentB)) {
			// If any segment is not semantically equal between the routes
			// it is not certain that the routes collide.
			return;
		}
	}

	// Both routes are guaranteed to collide such that one will never be matched.
	logger.warn(
		'router',
		`The route "${a.route}" is defined in both "${a.component}" and "${b.component}" using SSR mode. A dynamic SSR route cannot be defined more than once.`,
	);
	logger.warn('router', 'A collision will result in an hard error in following versions of Astro.');
}