Add validators module

src/validators/best_practices.py

@@ -0,0 +1,124 @@
+"""Best practices validation module."""
+
+from typing import List, Optional
+
+from ..models import Rule, Finding
+
+
+class BestPracticesValidator:
+    """Validates shell scripts for best practices."""
+
+    def __init__(self, custom_rules: Optional[List[Rule]] = None):
+        """Initialize the best practices validator with optional custom rules."""
+        self.rules = self.DEFAULT_PATTERNS.copy()
+        if custom_rules:
+            self.rules.extend(custom_rules)
+
+    DEFAULT_PATTERNS = [
+        Rule(
+            id="BEST001",
+            name="Missing set -e",
+            pattern=r"^[^#!]*set\s+-e",
+            severity="medium",
+            message="Script missing 'set -e' for automatic error handling",
+            suggestion="Add 'set -e' at the beginning of the script to exit on errors",
+        ),
+        Rule(
+            id="BEST002",
+            name="Missing set -u",
+            pattern=r"set\s+-[aeu]",
+            severity="medium",
+            message="Script missing 'set -u' to catch undefined variables",
+            suggestion="Add 'set -u' to catch usage of undefined variables",
+        ),
+        Rule(
+            id="BEST003",
+            name="Missing set -o pipefail",
+            pattern=r"set\s+-o\s+pipefail",
+            severity="medium",
+            message="Script missing 'set -o pipefail' for proper pipeline error handling",
+            suggestion="Add 'set -o pipefail' to capture errors in pipelines",
+        ),
+        Rule(
+            id="BEST004",
+            name="No error handling for command",
+            pattern=r"^(?!.*(\|\||\&\&|;|exit\s+\d+)).*$",
+            severity="medium",
+            message="Command without error handling",
+            suggestion="Add error handling with '|| exit 1' or '&&' operator",
+        ),
+        Rule(
+            id="BEST005",
+            name="Dangerous cp without -i",
+            pattern=r"cp\s+(?!.*-i)(?!.*--interactive)\s+\S+\s+\S+",
+            severity="medium",
+            message="cp without -i can overwrite files without warning",
+            suggestion="Use 'cp -i' for interactive mode or 'cp -n' for no-clobber",
+        ),
+        Rule(
+            id="BEST006",
+            name="Dangerous mv without -i",
+            pattern=r"mv\s+(?!.*-i)(?!.*--interactive)\s+\S+\s+\S+",
+            severity="medium",
+            message="mv without -i can overwrite files without warning",
+            suggestion="Use 'mv -i' for interactive mode or 'mv -n' for no-clobber",
+        ),
+        Rule(
+            id="STYLE001",
+            name="Use of deprecated backticks",
+            pattern=r"`[^`]+`",
+            severity="low",
+            message="Backticks for command substitution are deprecated",
+            suggestion="Use $() instead of backticks for command substitution",
+        ),
+        Rule(
+            id="STYLE002",
+            name="Long line detected",
+            pattern=r"^.{121,}$",
+            severity="low",
+            message="Line exceeds 120 characters",
+            suggestion="Consider breaking long lines for better readability",
+        ),
+        Rule(
+            id="STYLE003",
+            name="Use of cat with grep",
+            pattern=r"cat\s+\S+\s*\|\s*grep",
+            severity="low",
+            message="Useless use of cat",
+            suggestion="Use grep directly on the file instead of piping cat output",
+        ),
+        Rule(
+            id="STYLE004",
+            name="Missing shebang",
+            pattern=r"^[^#!].*$",
+            severity="low",
+            message="Script missing shebang line",
+            suggestion="Add appropriate shebang like #!/bin/bash or #!/usr/bin/env bash",
+        ),
+    ]
+
+    def validate(self, content: str, line_number: Optional[int] = None) -> List[Finding]:
+        """Validate content for best practices."""
+        findings = []
+        for rule in self.rules:
+            if not rule.enabled:
+                continue
+            matches = rule._compiled_pattern.finditer(content) if rule._compiled_pattern else []
+            for match in matches:
+                finding = Finding.from_match(rule, match, line_number, content)
+                findings.append(finding)
+        return findings
+
+    def validate_lines(self, lines: List[str]) -> List[Finding]:
+        """Validate multiple lines, tracking line numbers."""
+        findings = []
+        for line_number, line in enumerate(lines, start=1):
+            line_findings = self.validate(line, line_number)
+            for finding in line_findings:
+                finding.context = line
+            findings.extend(line_findings)
+        return findings
+
+    def check(self, command: str) -> List[Finding]:
+        """Check a single command for best practices issues."""
+        return self.validate(command)