Merge pull request #714 from SelYui/feature/AG-35374

Add support for regular expressions in `$app` modifier

Author: SelYui

docs/general/ad-filtering/create-own-filters.md

@@ -425,6 +425,19 @@ This modifier lets you narrow the rule coverage down to a specific application (
 
 For Mac, you can find out the bundle ID or the process name of the app by viewing the respective request details in the Filtering log.
 
+**Syntax**
+
+The modifier is a list of one or more expressions, each of which is matched against an application in a particular way depending on its type. These expressions are separated by the `|` symbol.
+
+```text
+applications = ["~"] entry_0 ["|" ["~"] entry_1 ["|" ["~"]entry_2 ["|" ... ["|" ["~"]entry_N]]]]
+entry_i = ( regular_app / wildcard_app / regexp )
+```
+
+- **`regular_app`** — a regular application name (`example.app`). It corresponds to the specified application and is matched lexicographically.
+- **`wildcard_app`** — an application name ending with a wildcard character `*`, such as `org.example.*` or `com.ad*`. It matches all applications whose names start with the specified prefix. Matching is done lexicographically.
+- **`regexp`** — a regular expression that starts and ends with `/`. It works the same way as the basic URL rules, but the characters `/`, `$`, `,`, and `|` must be escaped with `\`.
+
 **Examples**
 
 - `||baddomain.com^$app=org.example.app` — a rule to block requests that match the specified mask and are sent from the `org.example.app` Android app.
@@ -435,17 +448,32 @@ If you want the rule not to be applied to certain apps, start the app name with
 - `||baddomain.com^$app=~org.example.app` — a rule to block requests that match the specified mask and are sent from any app except for the `org.example.app`.
 - `||baddomain.com^$app=~org.example.app1|~org.example.app2` — same as above, but now two apps are excluded: `org.example.app1` and `org.example.app2`.
 
+You can use wildcards in the `$app` modifier:
+
+- `||baddomain.com^$app=org.example.*` — applies to all apps whose package names start with `org.example.`
+
+You can use regular expressions in the `$app` modifier by enclosing them in forward slashes `/.../`. This allows for more flexible matching — for example, targeting a group of apps from the same publisher or matching complex patterns.
+
+- `||baddomain.com^$app=/org\.example\.[a-z0-9_]+/` — applies to all apps whose package name starts with `org.example` (e.g. `org.example.app1`, `org.example.utility`, etc.).
+- `||baddomain.com^$app=/^org\.example\.app\$\|^org\.example\.[ab].*/` — applies to `org.example.app` and to any app whose package starts with `org.example.a` or `org.example.b`.
+
+The `$app` modifier supports combining all three types of entries — plain names, wildcards, and regular expressions — within the same rule, but it does not allow combining negated and non-negated expressions together.
+
+- `||example.com^$app=org.example.app|org.example.*|/org\.example\.[a-z]+/` — applies to `org.example.app`, all matching `org.example.*` and `org.example.[a-z]+` apps.
+
 :::caution Restrictions
 
-Apps in the modifier value cannot have a wildcard, e.g. `$app=com.*.music`.
-Rules with such modifier are considered invalid.
+- Apps in the modifier value cannot include a wildcard inside the string , e.g. `$app=com.*.music`.
+  Use a regular expression instead: `$app=/com\..*\.music/`.
+- You cannot combine negated (`~`) and non-negated expressions in the same `$app` modifier — this would be ambiguous.
 
 :::
 
 :::info Compatibility
 
 - Only AdGuard for Windows, Mac, Android are technically capable of using rules with `$app` modifier.
 - On Windows the process name is case-insensitive starting with AdGuard for Windows with [CoreLibs] v1.12 or later.
+- Support for regular expressions and for combining different types of entries (plain names, wildcards, and regular expressions) in the `$app` modifier is available starting from CoreLibs v1.19 or later.
 
 :::
 
@@ -1939,7 +1967,7 @@ In AdGuard for Windows, Mac and Android with [CoreLibs] v1.11 or later, JSONPath
 {
     "elems": [
         {
-            "a": {"b": {"c": 123}},
+            "a": {"b": {"c": 123}}
         },
         {
             "a": {"b": {"c": "abc"}}