feat: add support for the strategy parameter in component-name-unique rule

.changeset/vast-kids-add.md

@@ -0,0 +1,8 @@
+---
+'@redocly/cli': minor
+'@redocly/openapi-core': minor
+---
+
+Added a `strategy` option to the `component-name-unique` rule, matching the `--component-names-strategy` option of the `bundle` command.
+Set it to `title` to check the component names that bundling derives from each schema's `title`.
+With `strategy: title`, the rule also reports referenced schemas that have no `title`, because `bundle` can't name those and fails.

docs/@v2/commands/bundle.md

@@ -205,3 +205,6 @@ All other characters, including non-ASCII letters such as `é` or `я`, are repl
 Schemas without `title` can't be named using the `--component-names-strategy=title` strategy.
 The bundling process reports an error for such schemas.
 {% /admonition %}
+
+To catch name collisions before bundling, set the matching `strategy` option on the
+[`component-name-unique`](../rules/oas/component-name-unique.md) rule.

docs/@v2/rules/oas/component-name-unique.md

@@ -38,6 +38,7 @@ This clearly is not optimal. Having unique component names prevents these proble
 | parameters    | string | Possible values: `off`, `warn`, `error`. Default: not set.                               |
 | responses     | string | Possible values: `off`, `warn`, `error`. Default: not set.                               |
 | requestBodies | string | Possible values: `off`, `warn`, `error`. Default: not set.                               |
+| strategy      | string | Possible values: `basename`, `title`. Default: `basename`.                               |
 
 An example configuration:
 
@@ -48,8 +49,26 @@ rules:
     parameters: off
     responses: warn
     requestBodies: warn
+    strategy: basename
 ```
 
+### Component names strategy
+
+The rule predicts the component names that `bundle` produces, so `strategy` must match the
+[`--component-names-strategy`](../../commands/bundle.md#configure-the-component-names-strategy) option you bundle with.
+
+With the default `basename`, a schema pulled in from another file is named after the `$ref` fragment or the file name.
+Two files both called `Order.yaml` therefore collide, and the rule reports them.
+
+With `title`, the same schemas are named after their `title` field instead.
+Two files called `Order.yaml` with the titles `Order model` and `Order request` become `OrderModel` and `OrderRequest`, so the rule no longer reports them.
+Two schemas in differently named files that share a title do collide, and the rule reports those instead.
+
+The `title` strategy applies to every schema that `bundle` renames, which is every schema reached by a `$ref` that crosses a file boundary.
+A referenced schema that has no `title` can't be named under this strategy, and `bundle` fails without producing a file.
+The rule reports those schemas so you find them before bundling.
+For the uniqueness check itself, such a schema still falls back to its file name, so a name collision is reported as well.
+
 ## Examples
 
 Given this configuration:

packages/core/src/bundle/bundle-visitor.ts

@@ -1,5 +1,5 @@
 import { type RuleSeverity } from '../config/types.js';
-import { COMPONENT_NAME_CHARS, type SpecMajorVersion } from '../oas-types.js';
+import { type SpecMajorVersion } from '../oas-types.js';
 import {
   isAbsoluteUrl,
   replaceRef,
@@ -14,11 +14,9 @@ import {
 import { type ResolvedRefMap, type Document } from '../resolve.js';
 import { reportUnresolvedRef } from '../rules/common/no-unresolved-refs.js';
 import { type OasRef, type Oas3Discriminator, type Oas3Example } from '../typings/openapi.js';
+import { componentNameFromTitle } from '../utils/component-name-from-title.js';
 import { dequal } from '../utils/dequal.js';
-import { isPlainObject } from '../utils/is-plain-object.js';
-import { isString } from '../utils/is-string.js';
 import { makeRefId } from '../utils/make-ref-id.js';
-import { toPascalCase } from '../utils/to-pascal-case.js';
 import { type Oas3Visitor, type Oas2Visitor } from '../visitors.js';
 import { type UserContext, type ResolveResult, type NonUndefined, type Problem } from '../walk.js';
 import { type ComponentNamesStrategy } from './bundle-document.js';
@@ -320,14 +318,12 @@ export function makeBundleVisitor({
     return dequal(node, target.node);
   }
 
-  function componentNameFromTitle(
+  function resolveComponentNameFromTitle(
     target: ComponentTarget,
     componentsGroup: ComponentsGroup,
     ctx: UserContext
   ): { key: string; problem?: Problem } {
-    const { node } = target;
-    const title = isPlainObject(node) && isString(node.title) ? node.title.trim() : '';
-    const key = toPascalCase(title).replace(new RegExp(`[^${COMPONENT_NAME_CHARS}]`, 'g'), '-');
+    const { title, name: key } = componentNameFromTitle(target.node);
     const titleLocation = target.location.child('title');
 
     if (title === '') {
@@ -379,7 +375,7 @@ export function makeBundleVisitor({
     const componentsGroup = components[componentType];
 
     if (componentNamesStrategy === 'title' && componentType === schemaComponentType) {
-      const { key, problem } = componentNameFromTitle(target, componentsGroup, ctx);
+      const { key, problem } = resolveComponentNameFromTitle(target, componentsGroup, ctx);
       if (!problem) {
         firstSchemaLocationByName.set(key, target.location.child('title'));
         return key;