feat(ls): migrate disallowing equivalent paths in OAS2

packages/apidom-ls/src/config/codes.ts

@@ -667,6 +667,7 @@ enum ApilintCodes {
   OPENAPI2_PATH_TEMPLATE = 3040000,
   OPENAPI2_PATH_TEMPLATE_VALUE_WELL_FORMED = 3040100,
   OPENAPI2_PATH_TEMPLATE_VALUE_VALID,
+  OPENAPI2_PATH_TEMPLATE_VALUE_EQUIVALENT_NOT_ALLOWED,
 
   OPENAPI2_LICENSE = 3050000,
   OPENAPI2_LICENSE_FIELD_NAME_TYPE = 3050100,

packages/apidom-ls/src/config/openapi/path-template/lint/index.ts

@@ -1,6 +1,7 @@
 import valueWellFormedLint from './value--well-formed.ts';
 import valueValidLint from './value--valid.ts';
+import valueEquivalentNotAllowedLint from './value--equivalent-not-allowed.ts';
 
-const lints = [valueWellFormedLint, valueValidLint];
+const lints = [valueWellFormedLint, valueValidLint, valueEquivalentNotAllowedLint];
 
 export default lints;

packages/apidom-ls/src/config/openapi/path-template/lint/value--equivalent-not-allowed.ts

@@ -0,0 +1,17 @@
+import { DiagnosticSeverity } from 'vscode-languageserver-types';
+
+import ApilintCodes from '../../../codes.ts';
+import { LinterMeta } from '../../../../apidom-language-types.ts';
+import { OpenAPI2 } from '../../target-specs.ts';
+
+const valueEquivalentNotAllowedLint: LinterMeta = {
+  code: ApilintCodes.OPENAPI2_PATH_TEMPLATE_VALUE_EQUIVALENT_NOT_ALLOWED,
+  source: 'apilint',
+  message: 'Equivalent paths are not allowed',
+  severity: DiagnosticSeverity.Error,
+  linterFunction: 'apilintOpenAPIPathTemplateNoEquivalent',
+  marker: 'value',
+  targetSpecs: OpenAPI2,
+};
+
+export default valueEquivalentNotAllowedLint;

packages/apidom-ls/src/services/validation/linter-functions.ts

@@ -16,6 +16,7 @@ import {
   test as testPathTemplate,
   resolve as resolvePathTemplate,
   parse as parsePathTemplate,
+  isIdentical,
 } from 'openapi-path-templating';
 
 // eslint-disable-next-line import/no-cycle
@@ -1133,4 +1134,21 @@ export const standardLinterfunctions: FunctionItem[] = [
       return true;
     },
   },
+  {
+    functionName: 'apilintOpenAPIPathTemplateNoEquivalent',
+    function: (element: Element): boolean => {
+      const isFirstOccurrence = (currentKey: string, allKeys: unknown[]) => {
+        const firstIndex = allKeys.findIndex(
+          (e) => typeof e === 'string' && isIdentical(e, currentKey),
+        );
+
+        return allKeys[firstIndex] === currentKey;
+      };
+      const paths = element.parent?.parent;
+
+      return isStringElement(element) && isObject(paths)
+        ? isFirstOccurrence(element.toValue(), paths.keys())
+        : true;
+    },
+  },
 ];

packages/apidom-ls/test/fixtures/validation/oas/path-template-equivalent-not-allowed.yaml

@@ -0,0 +1,28 @@
+swagger: '2.0'
+info:
+  title: Test API
+  version: 1.0.0
+paths:
+  /items/{id}:
+    get:
+      summary: Get item by ID
+      parameters:
+        - name: id
+          in: path
+          required: true
+          type: string
+      responses:
+        200:
+          description: OK
+  /items/{itemId}:
+    get:
+      summary: Get item by itemId
+      parameters:
+        - name: itemId
+          in: path
+          required: true
+          type: string
+      responses:
+        200:
+          description: OK
+

packages/apidom-ls/test/validate.ts

@@ -3788,4 +3788,40 @@ describe('apidom-ls-validate', function () {
 
     languageService.terminate();
   });
+
+  it('oas 2.0 should not allow equivalent paths', async function () {
+    const spec = fs
+      .readFileSync(
+        path.join(
+          __dirname,
+          'fixtures',
+          'validation',
+          'oas',
+          'path-template-equivalent-not-allowed.yaml',
+        ),
+      )
+      .toString();
+    const doc: TextDocument = TextDocument.create(
+      'path-template-equivalent-not-allowed.yaml',
+      'yaml',
+      0,
+      spec,
+    );
+
+    const languageService: LanguageService = getLanguageService(contextNoSchema);
+
+    const result = await languageService.doValidation(doc);
+    const expected: Diagnostic[] = [
+      {
+        message: 'Equivalent paths are not allowed',
+        severity: 1,
+        code: 3040102,
+        source: 'apilint',
+        range: { start: { line: 16, character: 2 }, end: { line: 16, character: 17 } },
+      },
+    ];
+    assert.deepEqual(result, expected);
+
+    languageService.terminate();
+  });
 });