Add support for another $lookup use case

mchapman · mchapman · commit d84465db630d · 2025-04-06T11:47:26.000Z
diff --git a/src/server/data_form.ts b/src/server/data_form.ts
@@ -1391,6 +1391,34 @@ export class FormsAngular {
     if (findFuncQry) {
       retVal.unshift({ $match: findFuncQry });
     }
+
+    async function sanitiseLookupPipeline(stage) {
+      // can't think of a way to exploit this (if you add a findFunc) but it is the responsibility of the user
+      // to ensure that the pipeline returns fields used by the findFunc
+      console.log(`In some scenarios $lookups that use pipelines may not provide all the fields used by the 'findFunc' of a collection.
+              If you get no results returned this might be the explanation.`)
+
+      /* Sanitise the pipeline we are doing a lookup with, removing hidden fields from that collection */
+      const lookupCollectionName = stage.$lookup.from;
+      const lookupResource =
+          that.getResourceFromCollection(lookupCollectionName);
+      let lookupHiddenLookupFields = {};
+      if (lookupResource) {
+        if (lookupResource.options?.hide?.length > 0) {
+          lookupHiddenLookupFields = that.generateHiddenFields(
+              lookupResource,
+              false
+          );
+        }
+      }
+      stage.$lookup.pipeline = await that.sanitisePipeline(
+          stage.$lookup.pipeline,
+          lookupHiddenLookupFields,
+          findFuncQry,
+          req
+      );
+    }
+
     for (
       let pipelineSection = 0;
       pipelineSection < array.length;
@@ -1406,6 +1434,7 @@ export class FormsAngular {
         case "$addFields":
         case "$count":
         case "$group":
+        case "$unset":
         case "$limit":
         case "$replaceRoot":
         case "$replaceWith":
@@ -1461,15 +1490,21 @@ export class FormsAngular {
             let lookupProps = Object.keys(stage.$lookup);
             // First deal with simple $lookups with a single join field equality
             if (
-              lookupProps.length === 4 &&
+                (lookupProps.length === 4 || lookupProps.length === 5)&&
               lookupProps.includes("from") &&
               lookupProps.includes("localField") &&
               lookupProps.includes("foreignField") &&
               lookupProps.includes("as")
             ) {
               // If we are doing a lookup using an _id (so not fishing) we don't need to do the findFunc (see tkt #12399)
-              if (stage.$lookup.foreignField === "_id") {
-                needFindFunc = false;
+              if (lookupProps.length === 4) {
+                if (stage.$lookup.foreignField === "_id" || stage.$lookup.localField === "_id") {
+                  needFindFunc = false;
+                }
+              } else if (lookupProps.length === 5 && lookupProps.includes("pipeline")) {
+                await sanitiseLookupPipeline.call(this, stage);
+              } else {
+                throw new Error("Unsupported $lookup format");
               }
             } else if (
                 lookupProps.length === 4 &&
@@ -1478,30 +1513,7 @@ export class FormsAngular {
                 lookupProps.includes("pipeline") &&
                 lookupProps.includes("as")
             ) {
-              // can't think of a way to exploit this (if you add a findFunc) but it is the responsibility of the user
-              // to ensure that the pipeline returns fields used by the findFunc
-              console.log(`In some scenarios $lookups that use pipelines may not provide all the fields used by the 'findFunc' of a collection.
-              If you get no results returned this might be the explanation.`)
-
-              /* Sanitise the pipeline we are doing a lookup with, removing hidden fields from that collection */
-              const lookupCollectionName = stage.$lookup.from;
-              const lookupResource =
-                  that.getResourceFromCollection(lookupCollectionName);
-              let lookupHiddenLookupFields = {};
-              if (lookupResource) {
-                if (lookupResource.options?.hide?.length > 0) {
-                  lookupHiddenLookupFields = this.generateHiddenFields(
-                      lookupResource,
-                      false
-                  );
-                }
-              }
-              stage.$lookup.pipeline = await that.sanitisePipeline(
-                  stage.$lookup.pipeline,
-                  lookupHiddenLookupFields,
-                  findFuncQry,
-                  req
-              );
+              await sanitiseLookupPipeline.call(this, stage);
             } else {
               throw new Error(
                 `No support for $lookup of with properties ${lookupProps.join(', ')}`
