From e77387914c19f1c75d07c9544cae0b463499234e Mon Sep 17 00:00:00 2001
From: scripthunter7 <aronjuhasz@protonmail.com>
Date: Thu, 2 Jun 2022 15:22:01 +0200
Subject: [PATCH 1/8] TS declarations

---
 package.json   |  1 +
 src/index.d.ts | 52 ++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 53 insertions(+)
 create mode 100644 src/index.d.ts

diff --git a/package.json b/package.json
index c1bd44e..07e89e4 100644
--- a/package.json
+++ b/package.json
@@ -3,6 +3,7 @@
   "version": "1.0.13",
   "description": "A simple tool that compiles hosts blocklists from multiple sources",
   "main": "src/index.js",
+  "types": "src/index.d.ts",
   "repository": "https://github.com/AdguardTeam/HostlistCompiler",
   "author": "AdGuard",
   "license": "GPL-3.0",
diff --git a/src/index.d.ts b/src/index.d.ts
new file mode 100644
index 0000000..4a3caf9
--- /dev/null
+++ b/src/index.d.ts
@@ -0,0 +1,52 @@
+declare module '@adguard/hostlist-compiler' {
+    export type SourceType = 'adblock' | 'hosts';
+    export type Transformation = 'RemoveComments' | 'Compress' | 'RemoveModifiers' | 'Validate' | 'Deduplicate' | 'InvertAllow';
+
+    /** A source for the filter list */
+    export interface ISource {
+        /** Name of the source */
+        name?: string;
+        /** Path to a file or a URL */
+        source: string;
+        /** Type of the source */
+        type?: SourceType;
+        /** A list of the transformations that will be applied */
+        transformations?: Transformation[];
+        /** A list of rules (or wildcards) to exclude from the source. */
+        exclusions?: string[];
+        /** An array of exclusions sources. */
+        exclusions_sources?: string[];
+        /** A list of wildcards to include from the source. All rules that don't match these wildcards won't be included. */
+        inclusions?: string[];
+        /** A list of files with inclusions. */
+        inclusions_sources?: string[];
+    }
+
+    /** Configuration for the hostlist compiler */
+    export interface IConfiguration {
+        /** Filter list name */
+        name: string;
+        /** Filter list description */
+        description?: string;
+        /** Filter list homepage */
+        homepage?: string;
+        /** Filter list license */
+        license?: string;
+        /** An array of the filter list sources */
+        sources: ISource[];
+        /** A list of the transformations that will be applied */
+        transformations?: Transformation[];
+        /** A list of rules (or wildcards) to exclude from the source. */
+        exclusions?: string[];
+        /** An array of exclusions sources. */
+        exclusions_sources?: string[];
+        /** A list of wildcards to include from the source. All rules that don't match these wildcards won't be included. */
+        inclusions?: string[];
+        /** A list of files with inclusions. */
+        inclusions_sources?: string[];
+    }
+
+    declare async function compile(configuration: IConfiguration): Promise<string[]>;
+
+    export default compile;
+}

From 8526a602c0f3546d7b77bed2bd43ad32734f4576 Mon Sep 17 00:00:00 2001
From: scripthunter7 <aronjuhasz@protonmail.com>
Date: Thu, 2 Jun 2022 16:35:36 +0200
Subject: [PATCH 2/8] RemoveEmptyLines transformation

---
 src/index.d.ts                                |  2 +-
 src/schemas/configuration.schema.json         |  6 ++--
 src/transformations/remove-empty-lines.js     | 15 ++++++++++
 src/transformations/transform.js              |  5 ++++
 .../remove-empty-lines.test.js                | 29 +++++++++++++++++++
 5 files changed, 54 insertions(+), 3 deletions(-)
 create mode 100644 src/transformations/remove-empty-lines.js
 create mode 100644 test/transformations/remove-empty-lines.test.js

diff --git a/src/index.d.ts b/src/index.d.ts
index 4a3caf9..afe420e 100644
--- a/src/index.d.ts
+++ b/src/index.d.ts
@@ -1,6 +1,6 @@
 declare module '@adguard/hostlist-compiler' {
     export type SourceType = 'adblock' | 'hosts';
-    export type Transformation = 'RemoveComments' | 'Compress' | 'RemoveModifiers' | 'Validate' | 'Deduplicate' | 'InvertAllow';
+    export type Transformation = 'RemoveComments' | 'Compress' | 'RemoveModifiers' | 'Validate' | 'Deduplicate' | 'InvertAllow' | 'RemoveEmptyLines';
 
     /** A source for the filter list */
     export interface ISource {
diff --git a/src/schemas/configuration.schema.json b/src/schemas/configuration.schema.json
index bda3486..d1ece2c 100644
--- a/src/schemas/configuration.schema.json
+++ b/src/schemas/configuration.schema.json
@@ -41,7 +41,8 @@
           "Compress",
           "Validate",
           "Deduplicate",
-          "InvertAllow"
+          "InvertAllow",
+          "RemoveEmptyLines"
         ]
       }
     },
@@ -113,7 +114,8 @@
               "Compress",
               "Validate",
               "Deduplicate",
-              "InvertAllow"
+              "InvertAllow",
+              "RemoveEmptyLines"
             ]
           }
         },
diff --git a/src/transformations/remove-empty-lines.js b/src/transformations/remove-empty-lines.js
new file mode 100644
index 0000000..379a3fe
--- /dev/null
+++ b/src/transformations/remove-empty-lines.js
@@ -0,0 +1,15 @@
+const consola = require('consola');
+
+/**
+ * This is a very simple transformation that removes empty lines.
+ *
+ * @param {Array<string>} lines - lines/rules to transform
+ * @returns {Array<string>} filtered lines/rules
+ */
+function removeEmptyLines(lines) {
+    const filtered = lines.filter((line) => line.trim().length);
+    consola.info(`Removed ${lines.length - filtered.length} empty lines`);
+    return filtered;
+}
+
+module.exports = removeEmptyLines;
diff --git a/src/transformations/transform.js b/src/transformations/transform.js
index 9c76f3a..4f4ff71 100644
--- a/src/transformations/transform.js
+++ b/src/transformations/transform.js
@@ -6,6 +6,7 @@ const include = require('./include');
 const deduplicate = require('./deduplicate');
 const compress = require('./compress');
 const invertAllow = require('./invertallow');
+const removeEmptyLines = require('./remove-empty-lines');
 
 /**
  * Enum with all available transformations
@@ -17,6 +18,7 @@ const TRANSFORMATIONS = Object.freeze({
     Validate: 'Validate',
     Deduplicate: 'Deduplicate',
     InvertAllow: 'InvertAllow',
+    RemoveEmptyLines: 'RemoveEmptyLines',
 });
 
 /**
@@ -59,6 +61,9 @@ async function transform(rules, configuration, transformations) {
     if (transformations.indexOf(TRANSFORMATIONS.Deduplicate) !== -1) {
         transformed = deduplicate(transformed);
     }
+    if (transformations.indexOf(TRANSFORMATIONS.RemoveEmptyLines) !== -1) {
+        transformed = removeEmptyLines(transformed);
+    }
     return transformed;
 }
 
diff --git a/test/transformations/remove-empty-lines.test.js b/test/transformations/remove-empty-lines.test.js
new file mode 100644
index 0000000..4bb2e7c
--- /dev/null
+++ b/test/transformations/remove-empty-lines.test.js
@@ -0,0 +1,29 @@
+const removeEmptyLines = require('../../src/transformations/remove-empty-lines');
+
+describe('Remove empty lines', () => {
+    it('test with no empty lines', () => {
+        const rules = ['rule1', 'rule2'];
+        const filtered = removeEmptyLines(rules);
+        expect(filtered).toEqual(['rule1', 'rule2'])
+    });
+    it('test with one empty line at the end', () => {
+        const rules = ['rule1', 'rule2', ''];
+        const filtered = removeEmptyLines(rules);
+        expect(filtered).toEqual(['rule1', 'rule2'])
+    });
+    it('test with one empty line between the rules', () => {
+        const rules = ['rule1', '', 'rule2'];
+        const filtered = removeEmptyLines(rules);
+        expect(filtered).toEqual(['rule1', 'rule2'])
+    });
+    it('test with two empty line', () => {
+        const rules = ['rule1', '', '', 'rule2'];
+        const filtered = removeEmptyLines(rules);
+        expect(filtered).toEqual(['rule1', 'rule2'])
+    });
+    it('test with comments, empty lines', () => {
+        const rules = ['! aaa', 'rule1', '', '! bbb', '', '', 'rule2', '', '', '', '!ccc', '', ''];
+        const filtered = removeEmptyLines(rules);
+        expect(filtered).toEqual(['! aaa', 'rule1', '! bbb', 'rule2', '!ccc'])
+    });
+});

From 0cd05dc8fc40d6e8004562024f749d90394d68dc Mon Sep 17 00:00:00 2001
From: scripthunter7 <aronjuhasz@protonmail.com>
Date: Thu, 2 Jun 2022 16:45:19 +0200
Subject: [PATCH 3/8] InsertFinalNewLine transformation

---
 src/index.d.ts                                |  2 +-
 src/schemas/configuration.schema.json         |  6 ++--
 src/transformations/insert-final-new-line.js  | 17 +++++++++++
 src/transformations/transform.js              |  5 ++++
 .../insert-final-new-line.test.js             | 29 +++++++++++++++++++
 5 files changed, 56 insertions(+), 3 deletions(-)
 create mode 100644 src/transformations/insert-final-new-line.js
 create mode 100644 test/transformations/insert-final-new-line.test.js

diff --git a/src/index.d.ts b/src/index.d.ts
index afe420e..68da5b4 100644
--- a/src/index.d.ts
+++ b/src/index.d.ts
@@ -1,6 +1,6 @@
 declare module '@adguard/hostlist-compiler' {
     export type SourceType = 'adblock' | 'hosts';
-    export type Transformation = 'RemoveComments' | 'Compress' | 'RemoveModifiers' | 'Validate' | 'Deduplicate' | 'InvertAllow' | 'RemoveEmptyLines';
+    export type Transformation = 'RemoveComments' | 'Compress' | 'RemoveModifiers' | 'Validate' | 'Deduplicate' | 'InvertAllow' | 'RemoveEmptyLines' | 'InsertFinalNewLine';
 
     /** A source for the filter list */
     export interface ISource {
diff --git a/src/schemas/configuration.schema.json b/src/schemas/configuration.schema.json
index d1ece2c..939de4e 100644
--- a/src/schemas/configuration.schema.json
+++ b/src/schemas/configuration.schema.json
@@ -42,7 +42,8 @@
           "Validate",
           "Deduplicate",
           "InvertAllow",
-          "RemoveEmptyLines"
+          "RemoveEmptyLines",
+          "InsertFinalNewLine"
         ]
       }
     },
@@ -115,7 +116,8 @@
               "Validate",
               "Deduplicate",
               "InvertAllow",
-              "RemoveEmptyLines"
+              "RemoveEmptyLines",
+              "InsertFinalNewLine"
             ]
           }
         },
diff --git a/src/transformations/insert-final-new-line.js b/src/transformations/insert-final-new-line.js
new file mode 100644
index 0000000..9eec4b3
--- /dev/null
+++ b/src/transformations/insert-final-new-line.js
@@ -0,0 +1,17 @@
+const consola = require('consola');
+
+/**
+ * This is a very simple transformation that inserts a final new line.
+ *
+ * @param {Array<string>} lines - lines/rules to transform
+ * @returns {Array<string>} filtered lines/rules
+ */
+function insertFinalNewLine(lines) {
+    if (lines.length === 0 || (lines.length > 0 && lines[lines.length - 1].trim() != '')) {
+        lines.push('');
+    }
+    consola.info(`Final new line inserted`);
+    return lines;
+}
+
+module.exports = insertFinalNewLine;
diff --git a/src/transformations/transform.js b/src/transformations/transform.js
index 4f4ff71..200c4e7 100644
--- a/src/transformations/transform.js
+++ b/src/transformations/transform.js
@@ -7,6 +7,7 @@ const deduplicate = require('./deduplicate');
 const compress = require('./compress');
 const invertAllow = require('./invertallow');
 const removeEmptyLines = require('./remove-empty-lines');
+const insertFinalNewLine = require('./insert-final-new-line');
 
 /**
  * Enum with all available transformations
@@ -19,6 +20,7 @@ const TRANSFORMATIONS = Object.freeze({
     Deduplicate: 'Deduplicate',
     InvertAllow: 'InvertAllow',
     RemoveEmptyLines: 'RemoveEmptyLines',
+    InsertFinalNewLine: "InsertFinalNewLine"
 });
 
 /**
@@ -64,6 +66,9 @@ async function transform(rules, configuration, transformations) {
     if (transformations.indexOf(TRANSFORMATIONS.RemoveEmptyLines) !== -1) {
         transformed = removeEmptyLines(transformed);
     }
+    if (transformations.indexOf(TRANSFORMATIONS.InsertFinalNewLine) !== -1) {
+        transformed = insertFinalNewLine(transformed);
+    }
     return transformed;
 }
 
diff --git a/test/transformations/insert-final-new-line.test.js b/test/transformations/insert-final-new-line.test.js
new file mode 100644
index 0000000..01e962b
--- /dev/null
+++ b/test/transformations/insert-final-new-line.test.js
@@ -0,0 +1,29 @@
+const insertFinalNewLine = require('../../src/transformations/insert-final-new-line');
+
+describe('Insert final new line', () => {
+    it('test with empty file', () => {
+        const rules = [];
+        const filtered = insertFinalNewLine(rules);
+        expect(filtered).toEqual([''])
+    });
+    it('test with one empty line', () => {
+        const rules = [''];
+        const filtered = insertFinalNewLine(rules);
+        expect(filtered).toEqual([''])
+    });
+    it('test with one rule and one empty lines', () => {
+        const rules = ['rule1', ''];
+        const filtered = insertFinalNewLine(rules);
+        expect(filtered).toEqual(['rule1', ''])
+    });
+    it('test with many empty lines', () => {
+        const rules = ['rule1', '', ''];
+        const filtered = insertFinalNewLine(rules);
+        expect(filtered).toEqual(['rule1', '', ''])
+    });
+    it('test with one rule', () => {
+        const rules = ['rule1',];
+        const filtered = insertFinalNewLine(rules);
+        expect(filtered).toEqual(['rule1', ''])
+    });
+});

From dedcd66786e37e7c87da61201e08f8977eff7316 Mon Sep 17 00:00:00 2001
From: scripthunter7 <aronjuhasz@protonmail.com>
Date: Thu, 2 Jun 2022 16:53:33 +0200
Subject: [PATCH 4/8] compile JSDoc

---
 src/index.d.ts | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/src/index.d.ts b/src/index.d.ts
index 68da5b4..a170cde 100644
--- a/src/index.d.ts
+++ b/src/index.d.ts
@@ -46,6 +46,13 @@ declare module '@adguard/hostlist-compiler' {
         inclusions_sources?: string[];
     }
 
+    /**
+     * Compiles a filter list using the specified configuration.
+     *
+     * @param {*} configuration - compilation configuration.
+    See the repo README for the details on it.
+     * @returns {Array<string>} the array of rules.
+     */
     declare async function compile(configuration: IConfiguration): Promise<string[]>;
 
     export default compile;

From ddae442d791b514a19a3495542df8955e4b40eab Mon Sep 17 00:00:00 2001
From: scripthunter7 <aronjuhasz@protonmail.com>
Date: Thu, 2 Jun 2022 17:27:37 +0200
Subject: [PATCH 5/8] Update README

---
 README.md | 82 +++++++++++++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 79 insertions(+), 3 deletions(-)

diff --git a/README.md b/README.md
index be9d2fe..164f687 100644
--- a/README.md
+++ b/README.md
@@ -15,6 +15,8 @@ This is a simple tool that makes it easier to compile a [hosts blocklist](https:
   - [Validate](#validate)
   - [Deduplicate](#deduplicate)
   - [InvertAllow](#invertallow)
+  - [RemoveEmptyLines](#removeemptylines)
+  - [InsertFinalNewLine](#insertfinalnewline)
 - [How to build](#how-to-build)
 
 ## <a id="usage"></a> Usage
@@ -131,9 +133,9 @@ Examples:
 
 ### <a id="api"></a> API
 
-```
-npm i @adguard/hostlist-compiler
-```
+Install: `npm i @adguard/hostlist-compiler` or `yarn add @adguard/hostlist-compiler`
+
+#### JavaScript example:
 
 ```javascript
 const compile = require("@adguard/hostlist-compiler");
@@ -155,6 +157,28 @@ async function main() {
 main();
 ```
 
+#### TypeScript example:
+
+```typescript
+import HostlistCompiler, { IConfiguration as HostlistCompilerConfiguration } from '@adguard/hostlist-compiler';
+// or:
+// import compiler, { IConfiguration as CompilerConfiguration } from '@adguard/hostlist-compiler';
+import { writeFileSync } from 'fs';
+
+(async () => {
+    // Configuration
+    const config: HostlistCompilerConfiguration = {
+        // ...
+    };
+
+    // Compile filters
+    const result = await HostlistCompiler(config);
+
+    // Write to file
+    writeFileSync('custom-adguard-dns.txt', result.join('\n'));
+})();
+```
+
 ## <a id="transformations"></a> Transformations
 
 Here is the full list of transformations that are available:
@@ -165,6 +189,8 @@ Here is the full list of transformations that are available:
 4. `Validate`
 5. `Deduplicate`
 6. `InvertAllow`
+7. `RemoveEmptyLines`
+8. `InsertFinalNewLine`
 
 Please note that these transformations are are always applied in the order specified here.
 
@@ -266,6 +292,56 @@ Here's what we will have after applying this transformation:
 @@rule2
 ```
 
+### <a id="removeemptylines"></a> RemoveEmptyLines
+
+This is a very simple transformation that removes empty lines.
+
+**Example:**
+
+Original list:
+
+```
+rule1
+
+rule2
+
+
+rule3
+```
+
+Here's what we will have after applying this transformation:
+
+```
+rule1
+rule2
+rule3
+```
+
+### <a id="insertfinalnewline"></a> InsertFinalNewLine
+
+This is a very simple transformation that inserts a final new line.
+
+**Example:**
+
+Original list:
+
+```
+rule1
+rule2
+rule3
+```
+
+Here's what we will have after applying this transformation:
+
+```
+rule1
+rule2
+rule3
+
+```
+
+`RemoveEmptyLines` transformation has no effect on this new line because it precedes this transformation in the execution queue.
+
 ## <a id="how-to-build"></a> How to build
 
 - `yarn install` - installs dependencies

From c6fa552f2ae4c511aee40ba01751a1b3c13a1836 Mon Sep 17 00:00:00 2001
From: scripthunter7 <aronjuhasz@protonmail.com>
Date: Thu, 2 Jun 2022 22:06:27 +0200
Subject: [PATCH 6/8] TrimLines transformation

---
 README.md                               | 28 ++++++++++++-
 src/index.d.ts                          |  2 +-
 src/schemas/configuration.schema.json   |  2 +
 src/transformations/transform.js        |  5 +++
 src/transformations/trim-lines.js       | 16 ++++++++
 test/transformations/trim-lines.test.js | 52 +++++++++++++++++++++++++
 6 files changed, 103 insertions(+), 2 deletions(-)
 create mode 100644 src/transformations/trim-lines.js
 create mode 100644 test/transformations/trim-lines.test.js

diff --git a/README.md b/README.md
index 164f687..52504da 100644
--- a/README.md
+++ b/README.md
@@ -16,6 +16,7 @@ This is a simple tool that makes it easier to compile a [hosts blocklist](https:
   - [Deduplicate](#deduplicate)
   - [InvertAllow](#invertallow)
   - [RemoveEmptyLines](#removeemptylines)
+  - [TrimLines](#trimlines)
   - [InsertFinalNewLine](#insertfinalnewline)
 - [How to build](#how-to-build)
 
@@ -190,7 +191,8 @@ Here is the full list of transformations that are available:
 5. `Deduplicate`
 6. `InvertAllow`
 7. `RemoveEmptyLines`
-8. `InsertFinalNewLine`
+8. `TrimLines`
+9. `InsertFinalNewLine`
 
 Please note that these transformations are are always applied in the order specified here.
 
@@ -317,6 +319,30 @@ rule2
 rule3
 ```
 
+### <a id="trimlines"></a> TrimLines
+
+This is a very simple transformation that removes leading and trailing spaces/tabs.
+
+**Example:**
+
+Original list:
+
+```
+rule1
+   rule2
+rule3
+		rule4
+```
+
+Here's what we will have after applying this transformation:
+
+```
+rule1
+rule2
+rule3
+rule4
+```
+
 ### <a id="insertfinalnewline"></a> InsertFinalNewLine
 
 This is a very simple transformation that inserts a final new line.
diff --git a/src/index.d.ts b/src/index.d.ts
index a170cde..1eaa556 100644
--- a/src/index.d.ts
+++ b/src/index.d.ts
@@ -1,6 +1,6 @@
 declare module '@adguard/hostlist-compiler' {
     export type SourceType = 'adblock' | 'hosts';
-    export type Transformation = 'RemoveComments' | 'Compress' | 'RemoveModifiers' | 'Validate' | 'Deduplicate' | 'InvertAllow' | 'RemoveEmptyLines' | 'InsertFinalNewLine';
+    export type Transformation = 'RemoveComments' | 'Compress' | 'RemoveModifiers' | 'Validate' | 'Deduplicate' | 'InvertAllow' | 'RemoveEmptyLines' | 'TrimLines' | 'InsertFinalNewLine';
 
     /** A source for the filter list */
     export interface ISource {
diff --git a/src/schemas/configuration.schema.json b/src/schemas/configuration.schema.json
index 939de4e..cb3d559 100644
--- a/src/schemas/configuration.schema.json
+++ b/src/schemas/configuration.schema.json
@@ -43,6 +43,7 @@
           "Deduplicate",
           "InvertAllow",
           "RemoveEmptyLines",
+          "TrimLines",
           "InsertFinalNewLine"
         ]
       }
@@ -117,6 +118,7 @@
               "Deduplicate",
               "InvertAllow",
               "RemoveEmptyLines",
+              "TrimLines",
               "InsertFinalNewLine"
             ]
           }
diff --git a/src/transformations/transform.js b/src/transformations/transform.js
index 200c4e7..bc44a4f 100644
--- a/src/transformations/transform.js
+++ b/src/transformations/transform.js
@@ -7,6 +7,7 @@ const deduplicate = require('./deduplicate');
 const compress = require('./compress');
 const invertAllow = require('./invertallow');
 const removeEmptyLines = require('./remove-empty-lines');
+const trimLines = require('./trim-lines');
 const insertFinalNewLine = require('./insert-final-new-line');
 
 /**
@@ -20,6 +21,7 @@ const TRANSFORMATIONS = Object.freeze({
     Deduplicate: 'Deduplicate',
     InvertAllow: 'InvertAllow',
     RemoveEmptyLines: 'RemoveEmptyLines',
+    TrimLines: "TrimLines",
     InsertFinalNewLine: "InsertFinalNewLine"
 });
 
@@ -66,6 +68,9 @@ async function transform(rules, configuration, transformations) {
     if (transformations.indexOf(TRANSFORMATIONS.RemoveEmptyLines) !== -1) {
         transformed = removeEmptyLines(transformed);
     }
+    if (transformations.indexOf(TRANSFORMATIONS.TrimLines) !== -1) {
+        transformed = trimLines(transformed);
+    }
     if (transformations.indexOf(TRANSFORMATIONS.InsertFinalNewLine) !== -1) {
         transformed = insertFinalNewLine(transformed);
     }
diff --git a/src/transformations/trim-lines.js b/src/transformations/trim-lines.js
new file mode 100644
index 0000000..b89564a
--- /dev/null
+++ b/src/transformations/trim-lines.js
@@ -0,0 +1,16 @@
+const consola = require('consola');
+const _ = require('lodash');
+
+/**
+ * This is a very simple transformation that removes leading and trailing spaces/tabs.
+ *
+ * @param {Array<string>} lines - lines/rules to transform
+ * @returns {Array<string>} filtered lines/rules
+ */
+function trimLines(lines) {
+    lines = lines.map(line => _.trim(line, [' ', '\t']));
+    consola.info(`Lines trimmed.`);
+    return lines;
+}
+
+module.exports = trimLines;
diff --git a/test/transformations/trim-lines.test.js b/test/transformations/trim-lines.test.js
new file mode 100644
index 0000000..4e48965
--- /dev/null
+++ b/test/transformations/trim-lines.test.js
@@ -0,0 +1,52 @@
+const trimLines = require('../../src/transformations/trim-lines');
+
+describe('Trim lines', () => {
+    it('test with empty file', () => {
+        const rules = [];
+        const filtered = trimLines(rules);
+        expect(filtered).toEqual([]);
+    });
+    it('test with one empty line', () => {
+        const rules = [''];
+        const filtered = insertFinalNewLine(rules);
+        expect(filtered).toEqual(['']);
+    });
+    it('test with three rules', () => {
+        const rules = [
+            'rule1',
+            '   rule2 ',
+            '',
+            '          rule3         '
+        ];
+        const filtered = insertFinalNewLine(rules);
+        expect(filtered).toEqual([
+            'rule1',
+            'rule2',
+            '',
+            'rule3'
+        ]);
+    });
+    it('test with three rules and comments', () => {
+        const rules = [
+            'rule1',
+            '   rule2 ',
+            '',
+            '',
+            '! comment ',
+            '          rule3         ',
+            '    ! comment multiple   words    ',
+            '',
+        ];
+        const filtered = insertFinalNewLine(rules);
+        expect(filtered).toEqual([
+            'rule1',
+            'rule2',
+            '',
+            '',
+            '! comment',
+            'rule3',
+            '! comment multiple   words',
+            ''
+        ]);
+    });
+});

From b516ab928c789b5506d58d922796c3e4819dd63c Mon Sep 17 00:00:00 2001
From: scripthunter7 <aronjuhasz@protonmail.com>
Date: Thu, 2 Jun 2022 22:28:20 +0200
Subject: [PATCH 7/8] Async functions returns Promise in JSDoc

---
 src/compile-source.js            | 2 +-
 src/filter.js                    | 4 ++--
 src/index.d.ts                   | 2 +-
 src/index.js                     | 2 +-
 src/transformations/exclude.js   | 2 +-
 src/transformations/include.js   | 2 +-
 src/transformations/transform.js | 2 +-
 src/utils.js                     | 2 +-
 8 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/src/compile-source.js b/src/compile-source.js
index 7ba9ff8..4ddb67b 100644
--- a/src/compile-source.js
+++ b/src/compile-source.js
@@ -17,7 +17,7 @@ const { transform } = require('./transformations/transform');
  * Compiles an individual source according to it's configuration.
  *
  * @param {ListSource} source - source configuration.
- * @returns {Array<string>} array with the source rules
+ * @returns {Promise<Array<string>>} array with the source rules
  */
 async function compileSource(source) {
     consola.info(`Start compiling ${source.source}`);
diff --git a/src/filter.js b/src/filter.js
index d3cebab..807636e 100644
--- a/src/filter.js
+++ b/src/filter.js
@@ -7,7 +7,7 @@ const ruleUtils = require('./rule');
  * and return a final array with all the lines from all files.
  *
  * @param {Array<String>} sources - array of URLs.
- * @returns {Array<String>} array with all non-empty and non-comment lines.
+ * @returns {Promise<Array<String>>} array with all non-empty and non-comment lines.
  */
 async function downloadAll(sources) {
     let list = [];
@@ -32,7 +32,7 @@ async function downloadAll(sources) {
  * @param {Array<String>} rules - array of rules to apply
  * @param {Array<String>} sources - array of rules sources
  * (can be local or remote files)
- * @returns {Array<utils.Wildcard>} a list of wildcards to apply
+ * @returns {Promise<Array<utils.Wildcard>>} a list of wildcards to apply
  */
 async function prepareWildcards(rules, sources) {
     let list = [];
diff --git a/src/index.d.ts b/src/index.d.ts
index 1eaa556..4669375 100644
--- a/src/index.d.ts
+++ b/src/index.d.ts
@@ -51,7 +51,7 @@ declare module '@adguard/hostlist-compiler' {
      *
      * @param {*} configuration - compilation configuration.
     See the repo README for the details on it.
-     * @returns {Array<string>} the array of rules.
+     * @returns {Promise<Array<string>>} the array of rules.
      */
     declare async function compile(configuration: IConfiguration): Promise<string[]>;
 
diff --git a/src/index.js b/src/index.js
index 63f6d10..9615c34 100644
--- a/src/index.js
+++ b/src/index.js
@@ -65,7 +65,7 @@ function prepareSourceHeader(source) {
  *
  * @param {*} configuration - compilation configuration.
 See the repo README for the details on it.
- * @returns {Array<string>} the array of rules.
+ * @returns {Promise<Array<string>>} the array of rules.
  */
 async function compile(configuration) {
     consola.info('Starting the compiler');
diff --git a/src/transformations/exclude.js b/src/transformations/exclude.js
index 6ef3826..da6ea8d 100644
--- a/src/transformations/exclude.js
+++ b/src/transformations/exclude.js
@@ -9,7 +9,7 @@ const filterUtils = require('../filter');
  * @param {Array<String>} exclusions - array of exclusions to apply
  * @param {Array<String>} exclusionsSources - array of exclusion sources
  * (can be a local or remote file)
- * @returns {Array<String>} filtered array of rules
+ * @returns {Promise<Array<String>>} filtered array of rules
  */
 async function exclude(rules, exclusions, exclusionsSources) {
     if (_.isEmpty(exclusions) && _.isEmpty(exclusionsSources)) {
diff --git a/src/transformations/include.js b/src/transformations/include.js
index 9f2eefd..dd53859 100644
--- a/src/transformations/include.js
+++ b/src/transformations/include.js
@@ -9,7 +9,7 @@ const filterUtils = require('../filter');
  * @param {Array<String>} inclusions - array of inclusions to apply
  * @param {Array<String>} inclusionsSources - array of inclusions' sources
  * (can be a local or remote file)
- * @returns {Array<String>} filtered array of rules
+ * @returns {Promise<Array<String>>} filtered array of rules
  */
 async function include(rules, inclusions, inclusionsSources) {
     if (_.isEmpty(inclusions) && _.isEmpty(inclusionsSources)) {
diff --git a/src/transformations/transform.js b/src/transformations/transform.js
index bc44a4f..0edf2d6 100644
--- a/src/transformations/transform.js
+++ b/src/transformations/transform.js
@@ -31,7 +31,7 @@ const TRANSFORMATIONS = Object.freeze({
  * @param {Array<string>} rules - rules to transform
  * @param {*} configuration - transformation configuration.
  * @param {Array<string>} transformations - a list of transformations to apply to the rules.
- * @returns {Array<string>} rules after applying all transformations.
+ * @returns {Promise<Array<string>>} rules after applying all transformations.
  */
 async function transform(rules, configuration, transformations) {
     // If none specified -- apply all transformationss
diff --git a/src/utils.js b/src/utils.js
index 64e7b2d..1486fec 100644
--- a/src/utils.js
+++ b/src/utils.js
@@ -16,7 +16,7 @@ function isURL(str) {
  * Downloads (or reads from the disk) the specified source
  *
  * @param {*} urlOrPath url or path to a file
- * @returns {String} contents of the files
+ * @returns {Promise<String>} contents of the files
  */
 async function download(urlOrPath) {
     let str = '';

From 8d03fff718e4ec01cd6f4e9307e49ea2efe678cc Mon Sep 17 00:00:00 2001
From: scripthunter7 <aronjuhasz@protonmail.com>
Date: Thu, 2 Jun 2022 22:43:07 +0200
Subject: [PATCH 8/8] Fix typos, lint

---
 src/transformations/insert-final-new-line.js  |  4 +-
 src/transformations/transform.js              |  4 +-
 src/transformations/trim-lines.js             |  6 +-
 .../insert-final-new-line.test.js             | 35 +++++++---
 .../remove-empty-lines.test.js                | 68 ++++++++++++++++---
 test/transformations/trim-lines.test.js       | 12 ++--
 6 files changed, 98 insertions(+), 31 deletions(-)

diff --git a/src/transformations/insert-final-new-line.js b/src/transformations/insert-final-new-line.js
index 9eec4b3..7cd40ae 100644
--- a/src/transformations/insert-final-new-line.js
+++ b/src/transformations/insert-final-new-line.js
@@ -7,10 +7,10 @@ const consola = require('consola');
  * @returns {Array<string>} filtered lines/rules
  */
 function insertFinalNewLine(lines) {
-    if (lines.length === 0 || (lines.length > 0 && lines[lines.length - 1].trim() != '')) {
+    if (lines.length === 0 || (lines.length > 0 && lines[lines.length - 1].trim() !== '')) {
         lines.push('');
     }
-    consola.info(`Final new line inserted`);
+    consola.info('Final new line inserted');
     return lines;
 }
 
diff --git a/src/transformations/transform.js b/src/transformations/transform.js
index 0edf2d6..559fa5b 100644
--- a/src/transformations/transform.js
+++ b/src/transformations/transform.js
@@ -21,8 +21,8 @@ const TRANSFORMATIONS = Object.freeze({
     Deduplicate: 'Deduplicate',
     InvertAllow: 'InvertAllow',
     RemoveEmptyLines: 'RemoveEmptyLines',
-    TrimLines: "TrimLines",
-    InsertFinalNewLine: "InsertFinalNewLine"
+    TrimLines: 'TrimLines',
+    InsertFinalNewLine: 'InsertFinalNewLine',
 });
 
 /**
diff --git a/src/transformations/trim-lines.js b/src/transformations/trim-lines.js
index b89564a..8371f13 100644
--- a/src/transformations/trim-lines.js
+++ b/src/transformations/trim-lines.js
@@ -8,9 +8,9 @@ const _ = require('lodash');
  * @returns {Array<string>} filtered lines/rules
  */
 function trimLines(lines) {
-    lines = lines.map(line => _.trim(line, [' ', '\t']));
-    consola.info(`Lines trimmed.`);
-    return lines;
+    const transformed = lines.map((line) => _.trim(line, [' ', '\t']));
+    consola.info('Lines trimmed.');
+    return transformed;
 }
 
 module.exports = trimLines;
diff --git a/test/transformations/insert-final-new-line.test.js b/test/transformations/insert-final-new-line.test.js
index 01e962b..b98b7fd 100644
--- a/test/transformations/insert-final-new-line.test.js
+++ b/test/transformations/insert-final-new-line.test.js
@@ -4,26 +4,45 @@ describe('Insert final new line', () => {
     it('test with empty file', () => {
         const rules = [];
         const filtered = insertFinalNewLine(rules);
-        expect(filtered).toEqual([''])
+        expect(filtered).toEqual(['']);
     });
     it('test with one empty line', () => {
         const rules = [''];
         const filtered = insertFinalNewLine(rules);
-        expect(filtered).toEqual([''])
+        expect(filtered).toEqual(['']);
     });
     it('test with one rule and one empty lines', () => {
-        const rules = ['rule1', ''];
+        const rules = [
+            'rule1',
+            '',
+        ];
         const filtered = insertFinalNewLine(rules);
-        expect(filtered).toEqual(['rule1', ''])
+        expect(filtered).toEqual([
+            'rule1',
+            '',
+        ]);
     });
     it('test with many empty lines', () => {
-        const rules = ['rule1', '', ''];
+        const rules = [
+            'rule1',
+            '',
+            '',
+        ];
         const filtered = insertFinalNewLine(rules);
-        expect(filtered).toEqual(['rule1', '', ''])
+        expect(filtered).toEqual([
+            'rule1',
+            '',
+            '',
+        ]);
     });
     it('test with one rule', () => {
-        const rules = ['rule1',];
+        const rules = [
+            'rule1',
+        ];
         const filtered = insertFinalNewLine(rules);
-        expect(filtered).toEqual(['rule1', ''])
+        expect(filtered).toEqual([
+            'rule1',
+            '',
+        ]);
     });
 });
diff --git a/test/transformations/remove-empty-lines.test.js b/test/transformations/remove-empty-lines.test.js
index 4bb2e7c..86df05f 100644
--- a/test/transformations/remove-empty-lines.test.js
+++ b/test/transformations/remove-empty-lines.test.js
@@ -2,28 +2,76 @@ const removeEmptyLines = require('../../src/transformations/remove-empty-lines')
 
 describe('Remove empty lines', () => {
     it('test with no empty lines', () => {
-        const rules = ['rule1', 'rule2'];
+        const rules = [
+            'rule1',
+            'rule2',
+        ];
         const filtered = removeEmptyLines(rules);
-        expect(filtered).toEqual(['rule1', 'rule2'])
+        expect(filtered).toEqual([
+            'rule1',
+            'rule2',
+        ]);
     });
     it('test with one empty line at the end', () => {
-        const rules = ['rule1', 'rule2', ''];
+        const rules = [
+            'rule1',
+            'rule2',
+            '',
+        ];
         const filtered = removeEmptyLines(rules);
-        expect(filtered).toEqual(['rule1', 'rule2'])
+        expect(filtered).toEqual([
+            'rule1',
+            'rule2',
+        ]);
     });
     it('test with one empty line between the rules', () => {
-        const rules = ['rule1', '', 'rule2'];
+        const rules = [
+            'rule1',
+            '',
+            'rule2',
+        ];
         const filtered = removeEmptyLines(rules);
-        expect(filtered).toEqual(['rule1', 'rule2'])
+        expect(filtered).toEqual([
+            'rule1',
+            'rule2',
+        ]);
     });
     it('test with two empty line', () => {
-        const rules = ['rule1', '', '', 'rule2'];
+        const rules = [
+            'rule1',
+            '',
+            '',
+            'rule2',
+        ];
         const filtered = removeEmptyLines(rules);
-        expect(filtered).toEqual(['rule1', 'rule2'])
+        expect(filtered).toEqual([
+            'rule1',
+            'rule2',
+        ]);
     });
     it('test with comments, empty lines', () => {
-        const rules = ['! aaa', 'rule1', '', '! bbb', '', '', 'rule2', '', '', '', '!ccc', '', ''];
+        const rules = [
+            '! aaa',
+            'rule1',
+            '',
+            '! bbb',
+            '',
+            '',
+            'rule2',
+            '',
+            '',
+            '',
+            '!ccc',
+            '',
+            '',
+        ];
         const filtered = removeEmptyLines(rules);
-        expect(filtered).toEqual(['! aaa', 'rule1', '! bbb', 'rule2', '!ccc'])
+        expect(filtered).toEqual([
+            '! aaa',
+            'rule1',
+            '! bbb',
+            'rule2',
+            '!ccc',
+        ]);
     });
 });
diff --git a/test/transformations/trim-lines.test.js b/test/transformations/trim-lines.test.js
index 4e48965..0352247 100644
--- a/test/transformations/trim-lines.test.js
+++ b/test/transformations/trim-lines.test.js
@@ -8,7 +8,7 @@ describe('Trim lines', () => {
     });
     it('test with one empty line', () => {
         const rules = [''];
-        const filtered = insertFinalNewLine(rules);
+        const filtered = trimLines(rules);
         expect(filtered).toEqual(['']);
     });
     it('test with three rules', () => {
@@ -16,14 +16,14 @@ describe('Trim lines', () => {
             'rule1',
             '   rule2 ',
             '',
-            '          rule3         '
+            '          rule3         ',
         ];
-        const filtered = insertFinalNewLine(rules);
+        const filtered = trimLines(rules);
         expect(filtered).toEqual([
             'rule1',
             'rule2',
             '',
-            'rule3'
+            'rule3',
         ]);
     });
     it('test with three rules and comments', () => {
@@ -37,7 +37,7 @@ describe('Trim lines', () => {
             '    ! comment multiple   words    ',
             '',
         ];
-        const filtered = insertFinalNewLine(rules);
+        const filtered = trimLines(rules);
         expect(filtered).toEqual([
             'rule1',
             'rule2',
@@ -46,7 +46,7 @@ describe('Trim lines', () => {
             '! comment',
             'rule3',
             '! comment multiple   words',
-            ''
+            '',
         ]);
     });
 });