feat: add BracketAwareCsvParser to parse CSV file better (#494)

* fix: improve policy line parsing

This change makes the policy parser more robust and flexible, allowing for

* chore: remove csv-parse dependency from package.json

* refactor: use const instead of let for tokens array in Helper class

* fix: policy line parsing for nested expressions and quoted values

* feat: enhance csv-parse for policy

* refactor: reorganize policy parsing and loading logic

Author: HashCookie

package.json

@@ -52,7 +52,7 @@
     "@casbin/expression-eval": "^5.3.0",
     "await-lock": "^2.0.1",
     "buffer": "^6.0.3",
-    "csv-parse": "^5.3.5",
+    "csv-parse": "^5.5.6",
     "minimatch": "^7.4.2"
   },
   "files": [

src/persist/fileAdapter.ts

@@ -34,11 +34,11 @@ export class FileAdapter implements Adapter {
   private async loadPolicyFile(model: Model, handler: (line: string, model: Model) => void): Promise<void> {
     const bodyBuf = await (this.fs ? this.fs : mustGetDefaultFileSystem()).readFileSync(this.filePath);
     const lines = bodyBuf.toString().split('\n');
-    lines.forEach((n: string, index: number) => {
-      if (!n) {
+    lines.forEach((line: string) => {
+      if (!line || line.trim().startsWith('#')) {
         return;
       }
-      handler(n, model);
+      handler(line, model);
     });
   }
 

src/persist/helper.ts

@@ -1,23 +1,83 @@
 import { Model } from '../model';
 import { parse } from 'csv-parse/sync';
 
-export class Helper {
-  public static loadPolicyLine(line: string, model: Model): void {
+export interface IPolicyParser {
+  parse(line: string): string[][] | null;
+}
+
+export class BasicCsvParser implements IPolicyParser {
+  parse(line: string): string[][] | null {
     if (!line || line.trimStart().charAt(0) === '#') {
-      return;
+      return null;
     }
 
-    const tokens = parse(line, {
+    return parse(line, {
       delimiter: ',',
       skip_empty_lines: true,
       trim: true,
+      relax_quotes: true,
     });
+  }
+}
+
+export class BracketAwareCsvParser implements IPolicyParser {
+  private readonly baseParser: IPolicyParser;
+
+  constructor(baseParser: IPolicyParser = new BasicCsvParser()) {
+    this.baseParser = baseParser;
+  }
+
+  parse(line: string): string[][] | null {
+    const rawTokens = this.baseParser.parse(line);
+    if (!rawTokens || !rawTokens[0]) {
+      return null;
+    }
+
+    const tokens = rawTokens[0];
+    const processedTokens: string[] = [];
+    let currentToken = '';
+    let bracketCount = 0;
+
+    for (const token of tokens) {
+      for (const char of token) {
+        if (char === '(') bracketCount++;
+        else if (char === ')') bracketCount--;
+      }
+
+      currentToken += (currentToken ? ',' : '') + token;
+
+      if (bracketCount === 0) {
+        processedTokens.push(currentToken);
+        currentToken = '';
+      }
+    }
+
+    if (bracketCount !== 0) {
+      throw new Error(`Unmatched brackets in policy line: ${line}`);
+    }
+
+    return processedTokens.length > 0 ? [processedTokens] : null;
+  }
+}
+
+export class PolicyLoader {
+  private readonly parser: IPolicyParser;
 
+  constructor(parser: IPolicyParser = new BracketAwareCsvParser()) {
+    this.parser = parser;
+  }
+
+  loadPolicyLine(line: string, model: Model): void {
+    const tokens = this.parser.parse(line);
     if (!tokens || !tokens[0]) {
       return;
     }
 
-    const key = tokens[0][0];
+    let key = tokens[0][0].trim();
+    if (key.startsWith('"') && key.endsWith('"')) {
+      key = key.slice(1, -1);
+    }
+
     const sec = key.substring(0, 1);
     const item = model.model.get(sec);
     if (!item) {
@@ -28,6 +88,22 @@ export class Helper {
     if (!policy) {
       return;
     }
-    policy.policy.push(tokens[0].slice(1));
+
+    const values = tokens[0].slice(1).map((v) => {
+      if (v.startsWith('"') && v.endsWith('"')) {
+        v = v.slice(1, -1);
+      }
+      return v.replace(/""/g, '"').trim();
+    });
+
+    policy.policy.push(values);
+  }
+}
+
+export class Helper {
+  private static readonly policyLoader = new PolicyLoader();
+
+  public static loadPolicyLine(line: string, model: Model): void {
+    Helper.policyLoader.loadPolicyLine(line, model);
   }
 }

test/persist/helper.test.ts

@@ -45,7 +45,7 @@ m = r.sub == p.sub && r.obj == p.obj && r.act == p.act
     ['admin', '/', 'POST'],
     ['admin', '/', 'PUT'],
     ['admin', '/', 'DELETE'],
-    [' admin', '/ ', 'PATCH'],
+    ['admin', '/', 'PATCH'],
   ];
 
   testdata.forEach((n) => {

yarn.lock

@@ -2282,10 +2282,10 @@ cssstyle@^2.3.0:
   dependencies:
     cssom "~0.3.6"
 
-csv-parse@^5.3.5:
-  version "5.3.5"
-  resolved "https://registry.yarnpkg.com/csv-parse/-/csv-parse-5.3.5.tgz#9924bbba9f7056122f06b7af18edc1a7f022ce99"
-  integrity sha512-8O5KTIRtwmtD3+EVfW6BCgbwZqJbhTYsQZry12F1TP5RUp0sD9tp1UnCWic3n0mLOhzeocYaCZNYxOGSg3dmmQ==
+csv-parse@^5.5.6:
+  version "5.5.6"
+  resolved "https://registry.yarnpkg.com/csv-parse/-/csv-parse-5.5.6.tgz#0d726d58a60416361358eec291a9f93abe0b6b1a"
+  integrity sha512-uNpm30m/AGSkLxxy7d9yRXpJQFrZzVWLFBkS+6ngPcZkw/5k3L/jjFuj7tVnEpRn+QgmiXr21nDlhCiUK4ij2A==
 
 [email protected]:
   version "3.2.0"