perf(build): promote dependency-aware cache key to default, drop flag + --rebuild-dependents

.github/workflows/pullRequests.yml

@@ -112,7 +112,7 @@ jobs:
         run: yarn --immutable
         working-directory: ${{ github.base_ref }}
       - name: Build packages
-        run: yarn build --rebuild-dependents
+        run: yarn build
         working-directory: ${{ github.base_ref }}
       - uses: actions/cache@v5
         with:
@@ -149,7 +149,7 @@ jobs:
         run: yarn --immutable
         working-directory: ${{ github.base_ref }}
       - name: Build packages
-        run: yarn build --rebuild-dependents
+        run: yarn build
         working-directory: ${{ github.base_ref }}
       - name: Build core
         run: yarn webiny build core
@@ -233,7 +233,7 @@ jobs:
         run: yarn --immutable
         working-directory: ${{ github.base_ref }}
       - name: Build packages
-        run: yarn build --rebuild-dependents
+        run: yarn build
         working-directory: ${{ github.base_ref }}
       - name: Sync Dependencies Verification
         run: yarn verify-dependencies
@@ -335,7 +335,7 @@ jobs:
         run: yarn --immutable
         working-directory: ${{ github.base_ref }}
       - name: Build packages
-        run: yarn build --rebuild-dependents
+        run: yarn build
         working-directory: ${{ github.base_ref }}
       - name: Run tests
         run: ${{ matrix.testCommand.cmd }}
@@ -418,7 +418,7 @@ jobs:
         run: yarn --immutable
         working-directory: ${{ github.base_ref }}
       - name: Build packages
-        run: yarn build --rebuild-dependents
+        run: yarn build
         working-directory: ${{ github.base_ref }}
       - name: Run tests
         run: ${{ matrix.testCommand.cmd }}
@@ -511,7 +511,7 @@ jobs:
         run: yarn --immutable
         working-directory: ${{ github.base_ref }}
       - name: Build packages
-        run: yarn build --rebuild-dependents
+        run: yarn build
         working-directory: ${{ github.base_ref }}
       - name: Run tests
         run: ${{ matrix.testCommand.cmd }}
@@ -596,7 +596,7 @@ jobs:
         run: yarn --immutable
         working-directory: ${{ github.base_ref }}
       - name: Build packages
-        run: yarn build --rebuild-dependents
+        run: yarn build
         working-directory: ${{ github.base_ref }}
       - name: Run tests
         run: ${{ matrix.testCommand.cmd }}

.github/workflows/push.yml

@@ -58,7 +58,7 @@ jobs:
         run: yarn --immutable
         working-directory: v6
       - name: Build packages
-        run: yarn build --rebuild-dependents
+        run: yarn build
         working-directory: v6
       - uses: actions/cache@v5
         with:
@@ -133,7 +133,7 @@ jobs:
         run: yarn --immutable
         working-directory: v6
       - name: Build packages
-        run: yarn build --rebuild-dependents
+        run: yarn build
         working-directory: v6
       - name: Sync Dependencies Verification
         run: yarn verify-dependencies
@@ -226,7 +226,7 @@ jobs:
         run: yarn --immutable
         working-directory: v6
       - name: Build packages
-        run: yarn build --rebuild-dependents
+        run: yarn build
         working-directory: v6
       - name: Run tests
         run: ${{ matrix.testCommand.cmd }}
@@ -300,7 +300,7 @@ jobs:
         run: yarn --immutable
         working-directory: v6
       - name: Build packages
-        run: yarn build --rebuild-dependents
+        run: yarn build
         working-directory: v6
       - name: Run tests
         run: ${{ matrix.testCommand.cmd }}
@@ -382,7 +382,7 @@ jobs:
         run: yarn --immutable
         working-directory: v6
       - name: Build packages
-        run: yarn build --rebuild-dependents
+        run: yarn build
         working-directory: v6
       - name: Run tests
         run: ${{ matrix.testCommand.cmd }}
@@ -458,7 +458,7 @@ jobs:
         run: yarn --immutable
         working-directory: v6
       - name: Build packages
-        run: yarn build --rebuild-dependents
+        run: yarn build
         working-directory: v6
       - name: Run tests
         run: ${{ matrix.testCommand.cmd }}
@@ -534,7 +534,7 @@ jobs:
         run: yarn --immutable
         working-directory: v6
       - name: Build packages
-        run: yarn build --rebuild-dependents
+        run: yarn build
         working-directory: v6
       - name: Start Verdaccio local server
         working-directory: v6
@@ -695,7 +695,7 @@ jobs:
         run: yarn --immutable
         working-directory: v6
       - name: Build packages
-        run: yarn build --rebuild-dependents
+        run: yarn build
         working-directory: v6
       - name: Start Verdaccio local server
         working-directory: v6

.github/workflows/wac/pullRequests.wac.ts

@@ -25,8 +25,7 @@ import {
 const DIR_WEBINY_JS = "${{ github.base_ref }}";
 
 const installBuildSteps = createInstallBuildSteps({
-    workingDirectory: DIR_WEBINY_JS,
-    rebuildDependents: true
+    workingDirectory: DIR_WEBINY_JS
 });
 const yarnCacheSteps = createYarnCacheSteps({ workingDirectory: DIR_WEBINY_JS });
 const globalBuildCacheSteps = createGlobalBuildCacheSteps({ workingDirectory: DIR_WEBINY_JS });

.github/workflows/wac/push.wac.ts

@@ -21,8 +21,7 @@ const DIR_WEBINY_JS = "v6";
 const DIR_TEST_PROJECT = "new-webiny-project";
 
 const installBuildSteps = createInstallBuildSteps({
-    workingDirectory: DIR_WEBINY_JS,
-    rebuildDependents: true
+    workingDirectory: DIR_WEBINY_JS
 });
 const yarnCacheSteps = createYarnCacheSteps({
     workingDirectory: DIR_WEBINY_JS

.github/workflows/wac/steps/createInstallBuildSteps.ts

@@ -2,17 +2,15 @@ import { withCommonParams } from "./withCommonParams.js";
 
 interface CreateInstallBuildStepsParams {
     workingDirectory: string;
-    rebuildDependents?: boolean;
 }
 
 export const createInstallBuildSteps = (params: CreateInstallBuildStepsParams) => {
-    const rebuildDependents = params.rebuildDependents ?? false;
-    const buildCommand = rebuildDependents ? "yarn build --rebuild-dependents" : "yarn build";
-
     return withCommonParams(
         [
             { name: "Install dependencies", run: "yarn --immutable" },
-            { name: "Build packages", run: buildCommand }
+            // The build's dependency-aware cache key rebuilds dependents of any
+            // changed package on its own — no `--rebuild-dependents` needed.
+            { name: "Build packages", run: "yarn build" }
         ],
         { "working-directory": params.workingDirectory }
     );

scripts/buildPackages/src/buildPackages.ts

@@ -33,7 +33,6 @@ interface BuildOptions {
     p?: string | string[];
     debug?: boolean;
     cache?: boolean;
-    rebuildDependents?: boolean;
     buildOverrides?: string;
     safeReplace?: boolean;
 }
@@ -64,8 +63,7 @@ export const buildPackages = async () => {
 
     const { batches, packagesNoCache, allPackages, buildKeys } = await getBatches({
         cache: options.cache ?? true,
-        packagesWhitelist,
-        rebuildDependents: options.rebuildDependents
+        packagesWhitelist
     });
 
     if (!packagesNoCache.length) {

scripts/buildPackages/src/getBatches.ts

@@ -9,14 +9,13 @@ import { getBuildOutputFolder } from "./getBuildOutputFolder";
 import { getBuildMeta } from "./getBuildMeta";
 import { getPackageCacheFolderPath } from "./getPackageCacheFolderPath";
 import { distMatchesCache, recordCacheHash } from "./distContentHash";
-import { getEffectiveHashes, getOwnHashes, isDepAwareKeyEnabled } from "./getEffectiveHashes";
+import { getEffectiveHashes } from "./getEffectiveHashes";
 
 const { green } = chalk;
 
 interface GetBatchesOptions {
     cache?: boolean;
     packagesWhitelist?: string[];
-    rebuildDependents?: boolean;
 }
 
 export async function getBatches(options: GetBatchesOptions = {}) {
@@ -46,13 +45,11 @@ export async function getBatches(options: GetBatchesOptions = {}) {
         ignore: ["@webiny/project-utils"]
     });
 
-    // Build key per package. Default: own-source hash (original behavior).
-    // Experimental (WEBINY_EXPERIMENTAL_DEP_AWARE_CACHE): a dependency-aware key
-    // that also changes when any transitive dependency changes, so dependents of
-    // a changed package are detected as misses without `--rebuild-dependents`.
-    const buildKeys = isDepAwareKeyEnabled()
-        ? await getEffectiveHashes(allWorkspacePackages)
-        : await getOwnHashes(allWorkspacePackages);
+    // Dependency-aware build key per package: changes when the package's own
+    // source, any transitive workspace dependency, or any resolved third-party
+    // dependency changes — so dependents of a changed package are detected as
+    // misses on a plain build.
+    const buildKeys = await getEffectiveHashes(allWorkspacePackages);
 
     // 1. Determine for which packages we can use the cached built code, and for which we need to execute build.
     if (!useCache) {
@@ -77,36 +74,9 @@ export async function getBatches(options: GetBatchesOptions = {}) {
         }
     }
 
-    // 1.5 When using cache and --rebuild-dependents, also rebuild any package that depends on a changed package.
-    if (options.rebuildDependents && packagesNoCache.length > 0 && useCache) {
-        const dependents = workspaceGraph.getDependents();
-
-        const tainted = new Set(packagesNoCache.map(p => p.packageJson.name));
-        const queue = [...tainted];
-        while (queue.length > 0) {
-            const name = queue.pop()!;
-            for (const dependent of dependents.get(name) || []) {
-                if (!tainted.has(dependent)) {
-                    tainted.add(dependent);
-                    queue.push(dependent);
-                }
-            }
-        }
-
-        for (const name of tainted) {
-            if (packagesNoCache.some(p => p.packageJson.name === name)) continue;
-            const pkg = workspacesPackages.find(p => p.packageJson.name === name);
-            if (pkg) {
-                packagesNoCache.push(pkg);
-            }
-        }
-
-        for (let i = packagesUseCache.length - 1; i >= 0; i--) {
-            if (tainted.has(packagesUseCache[i].packageJson.name)) {
-                packagesUseCache.splice(i, 1);
-            }
-        }
-    }
+    // Dependents of a changed package no longer need explicit tainting: the
+    // dependency-aware key folds in dependency keys, so any dependent of a
+    // changed package is already a cache miss above.
 
     // 2. Let's use cached built code where possible.
     if (packagesUseCache.length) {

scripts/buildPackages/src/getEffectiveHashes.ts

@@ -7,33 +7,6 @@ import { PROJECT_ROOT } from "../../utils/getPackages.js";
 import { getPackageSourceHash } from "./getPackageSourceHash";
 import type { Package } from "./types";
 
-/**
- * Whether the experimental dependency-aware build key is enabled. OFF by
- * default: the build key is each package's own-source hash (original behavior),
- * and `--rebuild-dependents` remains the mechanism for rebuilding dependents.
- *
- * Enable with `WEBINY_EXPERIMENTAL_DEP_AWARE_CACHE=true` (or `1`) to make a
- * plain `yarn build` rebuild dependents of any changed package automatically.
- */
-export function isDepAwareKeyEnabled(): boolean {
-    const value = process.env.WEBINY_EXPERIMENTAL_DEP_AWARE_CACHE;
-    return value === "true" || value === "1";
-}
-
-/**
- * Own-source hash per package (no dependency folding) — the original,
- * non-dependency-aware build key. Used when the experimental key is disabled.
- */
-export async function getOwnHashes(allPackages: Package[]): Promise<Map<string, string>> {
-    const map = new Map<string, string>();
-    await Promise.all(
-        allPackages.map(async pkg => {
-            map.set(pkg.name, await getPackageSourceHash(pkg));
-        })
-    );
-    return map;
-}
-
 /**
  * Parses `yarn.lock` into a map of dependency descriptor → a token that changes
  * whenever the *resolved* package changes (its checksum, falling back to