remove fallback to collecitonId

Author: samwillis

packages/db/src/query/compiler/index.ts

@@ -45,12 +45,17 @@ export interface CompilationResult {
 }
 
 /**
- * Compiles a query2 IR into a D2 pipeline
+ * Compiles a query IR into a D2 pipeline
  * @param rawQuery The query IR to compile
- * @param inputs Mapping of collection names to input streams
+ * @param inputs Mapping of source aliases to input streams (e.g., `{ employee: input1, manager: input2 }`)
+ * @param collections Mapping of collection IDs to Collection instances
+ * @param subscriptions Mapping of source aliases to CollectionSubscription instances
+ * @param callbacks Mapping of source aliases to lazy loading callbacks
+ * @param lazySources Set of source aliases that should load data lazily
+ * @param optimizableOrderByCollections Map of collection IDs to order-by optimization info
  * @param cache Optional cache for compiled subqueries (used internally for recursion)
  * @param queryMapping Optional mapping from optimized queries to original queries
- * @returns A CompilationResult with the pipeline and collection WHERE clauses
+ * @returns A CompilationResult with the pipeline, source WHERE clauses, and alias metadata
  */
 export function compileQuery(
   rawQuery: QueryIR,
@@ -84,10 +89,9 @@ export function compileQuery(
   const aliasToCollectionId: Record<string, string> = {}
 
   // Create a map of source aliases to input streams.
-  // Note: During input resolution, alias keys take precedence over collection ID keys.
-  // This enables per-alias subscriptions: when looking up an input stream, we first check
-  // for `inputs[alias]` before falling back to `inputs[collectionId]`. This allows different
-  // aliases of the same collection (e.g., self-joins) to have independent filtered streams.
+  // Inputs MUST be keyed by alias (e.g., `{ employee: input1, manager: input2 }`),
+  // not by collection ID. This enables per-alias subscriptions where different aliases
+  // of the same collection (e.g., self-joins) maintain independent filtered streams.
   const sources: Record<string, KeyedStream> = {}
 
   // Process the FROM clause to get the main source
@@ -351,7 +355,7 @@ function processFrom(
 ): { alias: string; input: KeyedStream; collectionId: string } {
   switch (from.type) {
     case `collectionRef`: {
-      const input = allInputs[from.alias] ?? allInputs[from.collection.id]
+      const input = allInputs[from.alias]
       if (!input) {
         throw new CollectionInputNotFoundError(
           from.alias,

packages/db/src/query/compiler/joins.ts

@@ -431,7 +431,7 @@ function processJoinSource(
 ): { alias: string; input: KeyedStream; collectionId: string } {
   switch (from.type) {
     case `collectionRef`: {
-      const input = allInputs[from.alias] ?? allInputs[from.collection.id]
+      const input = allInputs[from.alias]
       if (!input) {
         throw new CollectionInputNotFoundError(
           from.alias,

packages/db/tests/query/compiler/subqueries.test.ts

@@ -172,7 +172,7 @@ describe(`Query2 Subqueries`, () => {
       const issuesInput = createIssueInput(graph)
       const { pipeline } = compileQuery(
         builtQuery,
-        { issues: issuesInput },
+        { issue: issuesInput },
         { issues: issuesCollection },
         {},
         {},
@@ -286,12 +286,12 @@ describe(`Query2 Subqueries`, () => {
       const compilation = compileQuery(
         builtQuery,
         {
-          issues: issuesInput,
-          users: usersInput,
+          issue: issuesInput,
+          user: usersInput,
         },
         { issues: issuesCollection, users: usersCollection },
         subscriptions,
-        { issues: dummyCallbacks, users: dummyCallbacks },
+        { issue: dummyCallbacks, user: dummyCallbacks },
         lazySources,
         {}
       )
@@ -395,12 +395,12 @@ describe(`Query2 Subqueries`, () => {
       const compilation = compileQuery(
         builtQuery,
         {
-          issues: issuesInput,
-          users: usersInput,
+          issue: issuesInput,
+          user: usersInput,
         },
         { issues: issuesCollection, users: usersCollection },
         subscriptions,
-        { issues: dummyCallbacks, users: dummyCallbacks },
+        { issue: dummyCallbacks, user: dummyCallbacks },
         lazyCollections,
         {}
       )
@@ -441,7 +441,7 @@ describe(`Query2 Subqueries`, () => {
       const issuesInput = createIssueInput(graph)
       const { pipeline } = compileQuery(
         builtQuery,
-        { issues: issuesInput },
+        { issue: issuesInput },
         { issues: issuesCollection },
         {},
         {},

packages/db/tests/query/compiler/subquery-caching.test.ts

@@ -50,10 +50,10 @@ describe(`Subquery Caching`, () => {
       },
     }
 
-    // Set up D2 inputs
+    // Set up D2 inputs - keyed by alias, not collection ID
     const graph = new D2()
     const userInput = graph.newInput<[number, any]>()
-    const inputs = { users: userInput }
+    const inputs = { u: userInput }
 
     // Test: Compile the main query twice - first without shared cache, then with shared cache
 
@@ -159,7 +159,7 @@ describe(`Subquery Caching`, () => {
 
     const graph = new D2()
     const userInput = graph.newInput<[number, any]>()
-    const inputs = { users: userInput }
+    const inputs = { u: userInput }
 
     // Create a shared cache
     const sharedCache = new WeakMap()
@@ -216,7 +216,7 @@ describe(`Subquery Caching`, () => {
 
     const graph = new D2()
     const userInput = graph.newInput<[number, any]>()
-    const inputs = { users: userInput }
+    const inputs = { u: userInput }
 
     const sharedCache = new WeakMap()
 
@@ -287,7 +287,7 @@ describe(`Subquery Caching`, () => {
 
     const graph = new D2()
     const userInput = graph.newInput<[number, any]>()
-    const inputs = { users: userInput }
+    const inputs = { u: userInput }
 
     const sharedCache = new WeakMap()