Added schema version check

Signed-off-by: Steve Springett <[email protected]>

Author: stevespringett

tools/src/main/js/linter/README.md

@@ -1,11 +1,11 @@
 # CycloneDX Schema Linter
 
-A modular linter for CycloneDX JSON schemas.
+A modular linter for CycloneDX JSON schemas, enforcing ISO House Style and Oxford English conventions.
 
 ## Requirements
 
 - Node.js >= 18.0.0
-- aspell with en_US and en_GB-ize dictionaries
+- aspell with English dictionaries (provides en_US and en_GB-ize)
 
 ```bash
 # Ubuntu/Debian
@@ -19,31 +19,32 @@ brew install aspell
 
 ```bash
 # Lint files
-node cli.js schema.json
-node cli.js schemas/*.schema.json
+node src/cli.js schema.json
+node src/cli.js schemas/*.schema.json
 
 # Exclude or include specific checks
-node cli.js --exclude formatting-indent schema.json
-node cli.js --include description-full-stop schema.json
+node src/cli.js --exclude formatting-indent schema.json
+node src/cli.js --include description-full-stop schema.json
 
 # Output formats: stylish (default), json, compact
-node cli.js --format json schema.json
+node src/cli.js --format json schema.json
 
 # List available checks
-node cli.js --list-checks
+node src/cli.js --list-checks
 ```
 
 ## Checks
 
 | Check | Description |
 |-------|-------------|
+| `schema-draft` | Validates `$schema` is JSON Schema 2020-12 and first property |
 | `schema-id-pattern` | Validates `$id` matches CycloneDX URL pattern |
 | `schema-comment` | Validates `$comment` contains required standard notice |
 | `formatting-indent` | Validates 2-space indentation |
 | `description-full-stop` | Descriptions must end with full stop |
 | `meta-enum-full-stop` | `meta:enum` values must end with full stop |
 | `property-name-american-english` | Property names use American English |
-| `description-oxford-english` | Descriptions use Oxford English (British with -ize) |
+| `description-oxford-english` | Descriptions use Oxford English (en_GB-ize) |
 | `no-uppercase-rfc` | No uppercase RFC 2119 keywords (MUST, SHALL, etc.) |
 | `no-must-word` | Use "shall" instead of "must" per ISO style |
 | `additional-properties-false` | Objects must have `additionalProperties: false` |
@@ -74,3 +75,7 @@ Create `.cdxlintrc.json` in your project root:
 ```bash
 npm test
 ```
+
+## Licence
+
+Apache-2.0

tools/src/main/js/linter/checks/index.js

@@ -37,6 +37,7 @@ export async function loadAllChecks() {
 // Export individual check modules for direct access if needed
 export * from './schema-id-pattern.check.js';
 export * from './schema-comment.check.js';
+export * from './schema-draft.check.js';
 export * from './formatting-indent.check.js';
 export * from './description-full-stop.check.js';
 export * from './meta-enum-full-stop.check.js';

tools/src/main/js/linter/checks/schema-draft.check.js

@@ -0,0 +1,93 @@
+/**
+ * CycloneDX Schema Linter - Schema Draft Check
+ * 
+ * Validates that the $schema property exists, has the correct value,
+ * and appears on the first line of the schema file.
+ * 
+ * @license Apache-2.0
+ */
+
+import { LintCheck, registerCheck, Severity } from '../index.js';
+
+/**
+ * Required $schema value
+ */
+const REQUIRED_SCHEMA = 'https://json-schema.org/draft/2020-12/schema';
+
+/**
+ * Check that validates the $schema property
+ */
+class SchemaDraftCheck extends LintCheck {
+  constructor() {
+    super(
+      'schema-draft',
+      'Schema Draft',
+      'Validates that $schema is present with the correct JSON Schema draft.',
+      Severity.ERROR
+    );
+  }
+
+  async run(schema, rawContent, config = {}) {
+    const issues = [];
+    
+    const requiredSchema = config.requiredSchema ?? REQUIRED_SCHEMA;
+    
+    // Check if $schema exists
+    if (!('$schema' in schema)) {
+      issues.push(this.createIssue(
+        'Schema is missing required $schema property.',
+        '$.$schema',
+        { expected: requiredSchema }
+      ));
+      return issues;
+    }
+    
+    // Check if $schema matches required value
+    if (schema.$schema !== requiredSchema) {
+      issues.push(this.createIssue(
+        `$schema must be "${requiredSchema}".`,
+        '$.$schema',
+        {
+          actual: schema.$schema,
+          expected: requiredSchema
+        }
+      ));
+    }
+    
+    // Check if $schema appears on first line
+    const lines = rawContent.split('\n');
+    let foundOnFirstLine = false;
+    
+    for (let i = 0; i < lines.length && i < 3; i++) {
+      const line = lines[i].trim();
+      // Skip opening brace
+      if (line === '{') continue;
+      
+      // First non-brace line should contain $schema
+      if (line.includes('"$schema"')) {
+        foundOnFirstLine = true;
+        break;
+      } else if (line.length > 0 && line !== '{') {
+        // Found something else first
+        break;
+      }
+    }
+    
+    if (!foundOnFirstLine) {
+      issues.push(this.createIssue(
+        '$schema must appear as the first property in the schema.',
+        '$.$schema',
+        { suggestion: 'Move $schema to be the first property after the opening brace.' }
+      ));
+    }
+    
+    return issues;
+  }
+}
+
+// Create and register the check
+const check = new SchemaDraftCheck();
+registerCheck(check);
+
+export { SchemaDraftCheck, REQUIRED_SCHEMA };
+export default check;