fix(mongodb): offer query operators by filter position

apps/desktop/src/lib/mongo/mongoCompletion.ts

@@ -4,10 +4,11 @@ import {
   COMMON_OPERATORS,
   EXPRESSION_OPERATORS,
   EXTENDED_JSON_VALUES,
+  FIELD_QUERY_OPERATORS,
   PIPELINE_STAGES,
   PUSH_MODIFIERS,
-  QUERY_OPERATORS,
   STAGE_OPTION_KEYS,
+  TOP_LEVEL_QUERY_OPERATORS,
   UPDATE_OPERATORS,
   UPDATE_OPERATOR_LABELS,
   VALUE_SNIPPETS,
@@ -34,6 +35,7 @@ export type MongoCompletionMode =
   | "method"
   | "cursorMethod"
   | "field"
+  | "filterField"
   | "fieldPath"
   | "fieldRef"
   | "value"
@@ -310,6 +312,10 @@ export function buildMongoCompletionItemsFromContext(context: MongoCompletionCon
     case "field":
       items = fieldItems(prefix, fields);
       break;
+    case "filterField":
+      // Fields lead; `$and` / `$or` and the other whole-filter operators follow once `$` is typed.
+      items = [...fieldItems(prefix, fields), ...specItems(TOP_LEVEL_QUERY_OPERATORS, prefix, "query operator", 80)];
+      break;
     case "fieldPath":
       items = fieldPathItems(prefix, fields);
       break;
@@ -325,7 +331,7 @@ export function buildMongoCompletionItemsFromContext(context: MongoCompletionCon
       break;
     case "queryOperator":
       // `{ _id: { $oid: ... } }` is as valid here as `{ _id: { $gt: ... } }`.
-      items = [...specItems(QUERY_OPERATORS, prefix, "query operator", 100), ...specItems(EXTENDED_JSON_VALUES, prefix, "extended JSON value", 90)];
+      items = [...specItems(FIELD_QUERY_OPERATORS, prefix, "query operator", 100), ...specItems(EXTENDED_JSON_VALUES, prefix, "extended JSON value", 90)];
       break;
     case "updateOperator":
       items = specItems(UPDATE_OPERATORS, prefix, "update operator", 100);
@@ -353,7 +359,7 @@ export function buildMongoCompletionItemsFromContext(context: MongoCompletionCon
 
 /** Modes whose items are built from the target collection's sampled fields. */
 export function mongoCompletionNeedsFields(mode: MongoCompletionMode): boolean {
-  return mode === "field" || mode === "fieldPath" || mode === "fieldRef" || mode === "expression";
+  return mode === "field" || mode === "filterField" || mode === "fieldPath" || mode === "fieldRef" || mode === "expression";
 }
 
 /** Modes whose items are built from the database's collection names. */
@@ -544,7 +550,7 @@ function classifyFilter(scan: MongoCallScan, rootIndex: number): MongoCompletion
   if (inner.kind === "array") return VALUE_ARRAY_OPERATORS.has(inner.key ?? "") && !scan.inString ? "value" : "none";
   if (inner.kind !== "object") return "none";
   if (scan.inValue) return scan.inString ? "none" : "value";
-  if (innerDepth(scan, rootIndex) === 0) return "field";
+  if (innerDepth(scan, rootIndex) === 0) return "filterField";
 
   // Inside a nested object: whose value is it?
   switch (inner.key) {
@@ -552,10 +558,10 @@ function classifyFilter(scan: MongoCallScan, rootIndex: number): MongoCompletion
       // An object inside an array: a sub-filter under `$and` / `$or` / `$nor`,
       // or an extended JSON wrapper such as `{ $oid: ... }` under `$in`.
       const parent = scan.stack[scan.stack.length - 2];
-      return parent?.kind === "array" && VALUE_ARRAY_OPERATORS.has(parent.key ?? "") ? "valueWrapper" : "field";
+      return parent?.kind === "array" && VALUE_ARRAY_OPERATORS.has(parent.key ?? "") ? "valueWrapper" : "filterField";
     }
     case "$elemMatch":
-      return "field";
+      return "filterField";
     case "$expr":
       return "expression";
     case "$jsonSchema":

apps/desktop/src/lib/mongo/mongoCompletionTables.ts

@@ -38,7 +38,11 @@ export function mongoOperatorItemType(apply: string): "snippet" | "keyword" {
   return apply.includes("${") ? "snippet" : "keyword";
 }
 
-export const QUERY_OPERATORS: MongoOperatorSpec[] = specs([
+/**
+ * Operators that constrain one field, valid inside `{ field: { ... } }`.
+ * `$and` / `$or` and friends are not: those go at the top level of a filter.
+ */
+export const FIELD_QUERY_OPERATORS: MongoOperatorSpec[] = specs([
   ["$eq", "Matches values equal to a value", "$eq: ${}"],
   ["$ne", "Matches values not equal to a value", "$ne: ${}"],
   ["$gt", "Matches values greater than a value", "$gt: ${}"],
@@ -47,18 +51,11 @@ export const QUERY_OPERATORS: MongoOperatorSpec[] = specs([
   ["$lte", "Matches values less than or equal to a value", "$lte: ${}"],
   ["$in", "Matches any value in an array", "$in: [${}]"],
   ["$nin", "Matches no value in an array", "$nin: [${}]"],
-  ["$and", "Joins clauses with a logical AND", "$and: [${}]"],
-  ["$or", "Joins clauses with a logical OR", "$or: [${}]"],
-  ["$nor", "Joins clauses with a logical NOR", "$nor: [${}]"],
   ["$not", "Inverts the effect of a query expression", "$not: { ${} }"],
   ["$exists", "Matches documents that have the field", "$exists: true"],
   ["$type", "Matches documents by BSON type", '$type: "${string}"'],
   ["$regex", "Matches a regular expression", '$regex: "${pattern}"'],
-  ["$text", "Performs a text search", '$text: { $search: "${text}" }'],
-  ["$expr", "Uses aggregation expressions in a query", "$expr: { ${} }"],
-  ["$jsonSchema", "Matches documents against a JSON schema", "$jsonSchema: { ${} }"],
   ["$mod", "Matches values by modulo division", "$mod: [${divisor}, ${remainder}]"],
-  ["$where", "Matches with a JavaScript predicate", '$where: "${expression}"'],
   ["$all", "Matches arrays containing all the values", "$all: [${}]"],
   ["$elemMatch", "Matches arrays with an element matching all criteria", "$elemMatch: { ${} }"],
   ["$size", "Matches arrays of a given length", "$size: ${}"],
@@ -72,6 +69,23 @@ export const QUERY_OPERATORS: MongoOperatorSpec[] = specs([
   ["$nearSphere", "Matches points near a point on a sphere", "$nearSphere: { ${} }"],
 ]);
 
+/**
+ * Operators that apply to the whole filter, valid at its top level and inside
+ * the sub-filters of `$and` / `$or` / `$nor` — never under a field.
+ */
+export const TOP_LEVEL_QUERY_OPERATORS: MongoOperatorSpec[] = specs([
+  ["$and", "Joins clauses with a logical AND", "$and: [${}]"],
+  ["$or", "Joins clauses with a logical OR", "$or: [${}]"],
+  ["$nor", "Joins clauses with a logical NOR", "$nor: [${}]"],
+  ["$expr", "Uses aggregation expressions in a query", "$expr: { ${} }"],
+  ["$text", "Performs a text search", '$text: { $search: "${text}" }'],
+  ["$where", "Matches with a JavaScript predicate", '$where: "${expression}"'],
+  ["$jsonSchema", "Matches documents against a JSON schema", "$jsonSchema: { ${} }"],
+]);
+
+/** Every query operator, for callers that do not care about position. */
+export const QUERY_OPERATORS: MongoOperatorSpec[] = [...FIELD_QUERY_OPERATORS, ...TOP_LEVEL_QUERY_OPERATORS];
+
 export const UPDATE_OPERATORS: MongoOperatorSpec[] = specs([
   ["$set", "Sets field values", "$set: { ${} }"],
   ["$unset", "Removes fields", '$unset: { ${field}: "" }'],