DRIVERS-3321 Restore "prefixPreview" and "suffixPreview" (#1954)

Author: kevinAlbs

source/client-side-encryption/client-side-encryption.md

@@ -1348,9 +1348,9 @@ insert or query. Drivers MUST document the following behavior:
 
 > To insert or query with an "Indexed", "Range", or "String" encrypted payload, use a `MongoClient` configured with
 > `AutoEncryptionOpts`. `AutoEncryptionOpts.bypassQueryAnalysis` may be true. `AutoEncryptionOpts.bypassAutoEncryption`
-> must be false. The "substringPreview" query type is in preview and should be used for experimental workloads only.
-> This feature is unstable and its security is not guaranteed until released as Generally Available (GA). The GA version
-> of this feature may not be backwards compatible with the preview version.
+> must be false. The "prefixPreview", "suffixPreview", and "substringPreview" query types are in preview and should be
+> used for experimental workloads only. This feature is unstable and its security is not guaranteed until released as
+> Generally Available (GA). The GA version of this feature may not be backwards compatible with the preview version.
 
 #### contentionFactor
 
@@ -1363,9 +1363,9 @@ One of the strings:
 
 - "equality"
 - "range"
-- "prefix"
+- "prefix" / "prefixPreview"
     - Used for the `$encStrStartsWith` operator.
-- "suffix"
+- "suffix" / "suffixPreview"
     - Used for the `$encStrEndsWith` operator.
 - "substringPreview"
     - Used for the `$encStrContains` operator.
@@ -2523,6 +2523,8 @@ explicit session parameter as described in the [Drivers Sessions Specification](
 
 ## Changelog
 
+- 2026-06-17: Restore `prefixPreview` and `suffixPreview` as experimental.
+
 - 2026-06-16: Update tests in response to server-side validation of payloads
     ([SERVER-91887](https://jira.mongodb.org/browse/SERVER-91887))
 

source/client-side-encryption/etc/data/encryptedFields-prefix-suffix-preview.json

@@ -0,0 +1,44 @@
+{
+    "fields": [
+        {
+            "keyId": {
+                "$binary": {
+                    "base64": "EjRWeBI0mHYSNBI0VniQEg==",
+                    "subType": "04"
+                }
+            },
+            "path": "encryptedText",
+            "bsonType": "string",
+            "queries": [
+                {
+                    "queryType": "prefixPreview",
+                    "strMinQueryLength": {
+                        "$numberInt": "2"
+                    },
+                    "strMaxQueryLength": {
+                        "$numberInt": "10"
+                    },
+                    "contention": {
+                        "$numberLong": "0"
+                    },
+                    "caseSensitive": true,
+                    "diacriticSensitive": true
+                },
+                {
+                    "queryType": "suffixPreview",
+                    "strMinQueryLength": {
+                        "$numberInt": "2"
+                    },
+                    "strMaxQueryLength": {
+                        "$numberInt": "10"
+                    },
+                    "contention": {
+                        "$numberLong": "0"
+                    },
+                    "caseSensitive": true,
+                    "diacriticSensitive": true
+                }
+            ]
+        }
+    ]
+}

source/client-side-encryption/tests/README.md

@@ -3878,6 +3878,9 @@ create the following collections with majority write concern:
 - `db.prefix-suffix-ci-di` using the `encryptedFields` option set to the contents of
     [encryptedFields-prefix-suffix-ci-di.json](https://github.com/mongodb/specifications/tree/master/source/client-side-encryption/etc/data/encryptedFields-prefix-suffix-ci-di.json).
     This step requires server 9.0.0+.
+- `db.prefix-suffix-preview` using the `encryptedFields` option set to the contents of
+    [encryptedFields-prefix-suffix-preview.json](https://github.com/mongodb/specifications/tree/master/source/client-side-encryption/etc/data/encryptedFields-prefix-suffix-preview.json).
+    This step requires server pre-9.0.0.
 - `db.substring` using the `encryptedFields` option set to the contents of
     [encryptedFields-substring.json](https://github.com/mongodb/specifications/tree/master/source/client-side-encryption/etc/data/encryptedFields-substring.json)
 - `db.substring-ci-di` using the `encryptedFields` option set to the contents of
@@ -3947,7 +3950,8 @@ class EncryptOpts {
 }
 ```
 
-Use `explicitEncryptedClient` to insert the following document into `db.prefix-suffix` with majority write concern:
+Use `explicitEncryptedClient` to insert the following document into `db.prefix-suffix` (if created) and
+`db.prefix-suffix-preview` (if created) with majority write concern:
 
 ```javascript
 { "_id": 0, "encryptedText": <encrypted 'foobarbaz'> }
@@ -3980,15 +3984,20 @@ Use `explicitEncryptedClient` to insert the following document into `db.substrin
 
 #### Case 1: can find a document by prefix
 
-This test case requires MongoDB server 9.0.0+ and libmongocrypt 1.19.0+.
+Run this case multiple times with the following sets of parameters:
+
+- `queryType=prefix` and `collection=prefix-suffix`
+    - Require server 9.0.0+ and libmongocrypt 1.19.0+.
+- `queryType=prefixPreview` and `collection=prefix-suffix-preview`
+    - Require server pre-9.0.0 and libmongocrypt 1.19.1+.
 
 Use `clientEncryption.encrypt()` to encrypt the string `"foo"` with the following `EncryptOpts`:
 
 ```typescript
 class EncryptOpts {
    keyId : <key1ID>,
    algorithm: "String",
-   queryType: "prefix",
+   queryType: "<queryType>",
    contentionFactor: 0,
    stringOpts: StringOpts {
       caseSensitive: true,
@@ -4001,7 +4010,7 @@ class EncryptOpts {
 }
 ```
 
-Use `explicitEncryptedClient` to run a "find" operation on the `db.prefix-suffix` collection with the following filter:
+Use `explicitEncryptedClient` to run a "find" operation on the `db.<collection>` collection with the following filter:
 
 ```javascript
 { $expr: { $encStrStartsWith: {input: '$encryptedText', prefix: <encrypted 'foo'>} } }
@@ -4015,15 +4024,20 @@ Assert the following document is returned:
 
 #### Case 2: can find a document by suffix
 
-This test case requires MongoDB server 9.0.0+ and libmongocrypt 1.19.0+.
+Run this case multiple times with the following sets of parameters:
+
+- `queryType=suffix` and `collection=prefix-suffix`
+    - Require server 9.0.0+ and libmongocrypt 1.19.0+.
+- `queryType=suffixPreview` and `collection=prefix-suffix-preview`
+    - Require server pre-9.0.0 and libmongocrypt 1.19.1+.
 
 Use `clientEncryption.encrypt()` to encrypt the string `"baz"` with the following `EncryptOpts`:
 
 ```typescript
 class EncryptOpts {
    keyId : <key1ID>,
    algorithm: "String",
-   queryType: "suffix",
+   queryType: "<queryType>",
    contentionFactor: 0,
    stringOpts: StringOpts {
       caseSensitive: true,
@@ -4036,7 +4050,7 @@ class EncryptOpts {
 }
 ```
 
-Use `explicitEncryptedClient` to run a "find" operation on the `db.prefix-suffix` collection with the following filter:
+Use `explicitEncryptedClient` to run a "find" operation on the `db.<collection>` collection with the following filter:
 
 ```javascript
 { $expr: { $encStrEndsWith: {input: '$encryptedText', suffix: <encrypted 'baz'>} } }
@@ -4050,15 +4064,20 @@ Assert the following document is returned:
 
 #### Case 3: assert no document found by prefix
 
-This test case requires MongoDB server 9.0.0+ and libmongocrypt 1.19.0+.
+Run this case multiple times with the following sets of parameters:
+
+- `queryType=prefix` and `collection=prefix-suffix`
+    - Require server 9.0.0+ and libmongocrypt 1.19.0+.
+- `queryType=prefixPreview` and `collection=prefix-suffix-preview`
+    - Require server pre-9.0.0 and libmongocrypt 1.19.1+.
 
 Use `clientEncryption.encrypt()` to encrypt the string `"baz"` with the following `EncryptOpts`:
 
 ```typescript
 class EncryptOpts {
    keyId : <key1ID>,
    algorithm: "String",
-   queryType: "prefix",
+   queryType: "<queryType>",
    contentionFactor: 0,
    stringOpts: StringOpts {
       caseSensitive: true,
@@ -4071,7 +4090,7 @@ class EncryptOpts {
 }
 ```
 
-Use `explicitEncryptedClient` to run a "find" operation on the `db.prefix-suffix` collection with the following filter:
+Use `explicitEncryptedClient` to run a "find" operation on the `db.<collection>` collection with the following filter:
 
 ```javascript
 { $expr: { $encStrStartsWith: {input: '$encryptedText', prefix: <encrypted 'baz'>} } }
@@ -4081,15 +4100,20 @@ Assert that no documents are returned.
 
 #### Case 4: assert no document found by suffix
 
-This test case requires MongoDB server 9.0.0+ and libmongocrypt 1.19.0+.
+Run this case multiple times with the following sets of parameters:
+
+- `queryType=suffix` and `collection=prefix-suffix`
+    - Require server 9.0.0+ and libmongocrypt 1.19.0+.
+- `queryType=suffixPreview` and `collection=prefix-suffix-preview`
+    - Require server pre-9.0.0 and libmongocrypt 1.19.1+.
 
 Use `clientEncryption.encrypt()` to encrypt the string `"foo"` with the following `EncryptOpts`:
 
 ```typescript
 class EncryptOpts {
    keyId : <key1ID>,
    algorithm: "String",
-   queryType: "suffix",
+   queryType: "<queryType>",
    contentionFactor: 0,
    stringOpts: StringOpts {
       caseSensitive: true,
@@ -4102,7 +4126,7 @@ class EncryptOpts {
 }
 ```
 
-Use `explicitEncryptedClient` to run a "find" operation on the `db.prefix-suffix` collection with the following filter:
+Use `explicitEncryptedClient` to run a "find" operation on the `db.<collection>` collection with the following filter:
 
 ```javascript
 { $expr: { $encStrEndsWith: {input: '$encryptedText', suffix: <encrypted 'foo'>} } }