feat(cli): normalize variable names for OpenAPI paths

Non-word characters in variable names for OpenAPI paths are not allowed
by `@loopback/rest`.

packages/cli/generators/openapi/spec-helper.js

@@ -203,7 +203,13 @@ function buildMethodSpec(controllerSpec, op, options) {
       const pType = mapSchemaType(p.schema, options);
       addImportsForType(pType);
       comments.push(`@param ${name} ${p.description || ''}`);
-      return `@param({name: '${p.name}', in: '${p.in}'}) ${name}: ${
+
+      // Normalize parameter name to match `\w`
+      let paramName = p.name;
+      if (p.in === 'path') {
+        paramName = paramName.replace(/[^\w]+/g, '_');
+      }
+      return `@param({name: '${paramName}', in: '${p.in}'}) ${name}: ${
         pType.signature
       }`;
     });
@@ -285,10 +291,17 @@ function buildMethodSpec(controllerSpec, op, options) {
     returnType.signature
   }>`;
   comments.unshift(op.spec.description || '', '\n');
+
+  // Normalize path variable names to alphanumeric characters including the
+  // underscore (Equivalent to [A-Za-z0-9_]). Please note `@loopback/rest`
+  // does not allow other characters that don't match `\w`.
+  const opPath = op.path.replace(/\{[^\}]+\}/g, varName =>
+    varName.replace(/[^\w\{\}]+/g, '_'),
+  );
   const methodSpec = {
     description: op.spec.description,
     comments,
-    decoration: `@operation('${op.verb}', '${op.path}')`,
+    decoration: `@operation('${op.verb}', '${opPath}')`,
     signature,
   };
   if (op.spec['x-implementation']) {

packages/cli/test/fixtures/openapi/3.0/customer.yaml

@@ -69,15 +69,15 @@ paths:
             application/json:
               schema:
                 $ref: '#/components/schemas/Customer'
-  /customers/{id}:
+  /customers/{customer-id}:
     get:
       tags:
         - Customer
       description: Returns a customer based on a single ID
       x-implementation: "return {id: id, 'first-name': 'John', last-name: 'Smith'};"
       operationId: find customer by id
       parameters:
-        - name: id
+        - name: customer-id
           in: path
           description: ID of customer to fetch
           required: true

packages/cli/test/unit/openapi/controller-spec.unit.js

@@ -59,13 +59,13 @@ describe('openapi to controllers/models', () => {
             comments: [
               'Returns a customer based on a single ID',
               '\n',
-              '@param id ID of customer to fetch',
+              '@param customerId ID of customer to fetch',
               '@returns customer response',
             ],
-            decoration: "@operation('get', '/customers/{id}')",
+            decoration: "@operation('get', '/customers/{customer_id}')",
             signature:
-              "async findCustomerById(@param({name: 'id', in: 'path'}) " +
-              'id: number): Promise<Customer>',
+              "async findCustomerById(@param({name: 'customer_id', " +
+              "in: 'path'}) customerId: number): Promise<Customer>",
             implementation:
               "return {id: id, 'first-name': 'John', last-name: 'Smith'};",
           },