refactor(project): Fix cache invalidation tracking

Author: RandomByte

packages/project/lib/build/cache/ProjectBuildCache.js

@@ -815,10 +815,10 @@ export default class ProjectBuildCache {
 				// Source index is up-to-date, awaiting dependency indices validation
 				// Status remains at initializing
 				this.#cacheState = CACHE_STATES.INITIALIZING;
+				this.#cachedSourceSignature = resourceIndex.getSignature();
 			}
 			this.#sourceIndex = resourceIndex;
-			this.#cachedSourceSignature = resourceIndex.getSignature();
-			this.#changedProjectSourcePaths = changedPaths;
+			// Since all source files are part of the result, declare any detected changes as newly written resources
 			this.#writtenResultResourcePaths = changedPaths;
 		} else {
 			// No index cache found, create new index
@@ -853,6 +853,7 @@ export default class ProjectBuildCache {
 			log.verbose(`Source resource index for project ${this.#project.getName()} updated: ` +
 				`${removed.length} removed, ${added.length} added, ${updated.length} updated resources.`);
 			const changedPaths = [...removed, ...added, ...updated];
+			// Since all source files are part of the result, declare any detected changes as newly written resources
 			for (const resourcePath of changedPaths) {
 				if (!this.#writtenResultResourcePaths.includes(resourcePath)) {
 					this.#writtenResultResourcePaths.push(resourcePath);

packages/project/lib/build/cache/ResourceRequestManager.js

@@ -244,11 +244,16 @@ class ResourceRequestManager {
 				await resourceIndex.upsertResources(resourcesToUpdate);
 			}
 		}
+		let hasChanges;
 		if (this.#useDifferentialUpdate) {
-			return await this.#flushTreeChangesWithDiffTracking();
+			hasChanges = await this.#flushTreeChangesWithDiffTracking();
 		} else {
-			return await this.#flushTreeChangesWithoutDiffTracking();
+			hasChanges = await this.#flushTreeChangesWithoutDiffTracking();
 		}
+		if (hasChanges) {
+			this.#hasNewOrModifiedCacheEntries = true;
+		}
+		return hasChanges;
 	}
 
 	/**
@@ -461,6 +466,9 @@ class ResourceRequestManager {
 	 * @returns {string} Special signature "X" indicating no requests
 	 */
 	recordNoRequests() {
+		if (!this.#unusedAtLeastOnce) {
+			this.#hasNewOrModifiedCacheEntries = true;
+		}
 		this.#unusedAtLeastOnce = true;
 		return "X"; // Signature for when no requests were made
 	}
@@ -477,6 +485,7 @@ class ResourceRequestManager {
 	 * @returns {Promise<object>} Object containing setId and signature of the resource index
 	 */
 	async #addRequestSet(requests, reader) {
+		this.#hasNewOrModifiedCacheEntries = true;
 		// Try to find an existing request set that we can reuse
 		let setId = this.#requestGraph.findExactMatch(requests);
 		let resourceIndex;