fix(docs): merge together style docs from multiple CSS files

This fixes a bug where although multiple stylesheets were being
processed by the `ext-transforms-plugin` we were not properly merging
the style documentation for all of those stylesheets, leading to a race
condition where whichever file was processed last would set the
style docs for the whole component. Not good!

To fix the issue we just need to merge the style docs for the various
stylesheets together (de-duping on the `name` property).

This also adds a test project in `test/docs-readme` which exercises this
functionality.

STENCIL-1271

cspell-wordlist.txt

@@ -112,6 +112,7 @@ stenciljs
 stnl
 stringification
 stringified
+styleurls
 subdir
 templating
 timespan

src/compiler/bundle/ext-transforms-plugin.ts

@@ -1,4 +1,4 @@
-import { hasError, isOutputTargetDistCollection, join, normalizeFsPath, relative } from '@utils';
+import { hasError, isOutputTargetDistCollection, join, mergeIntoWith, normalizeFsPath, relative } from '@utils';
 import type { Plugin } from 'rollup';
 
 import type * as d from '../../declarations';
@@ -163,7 +163,8 @@ export const extTransformsPlugin = (
 
         // Set style docs
         if (cmp) {
-          cmp.styleDocs = cssTransformResults.styleDocs;
+          cmp.styleDocs ||= [];
+          mergeIntoWith(cmp.styleDocs, cssTransformResults.styleDocs, (docs) => docs.name);
         }
 
         // Track dependencies

src/utils/helpers.ts

@@ -130,6 +130,30 @@ export const unique = <T, K>(array: T[], predicate: (item: T) => K = (i) => i as
   });
 };
 
+/**
+ * Merge elements of an array into an existing array, using a predicate to
+ * determine uniqueness and only adding elements when they are not present in
+ * the first array.
+ *
+ * **Note**: this mutates the target array! This is intentional to avoid
+ * unnecessary array allocation, but be sure that it's what you want!
+ *
+ * @param target the target array, to which new unique items should be added
+ * @param newItems a list of new items, some (or all!) of which may be added
+ * @param mergeWith a predicate function which reduces the items in `target`
+ * and `newItems` to a value which can be equated with `===` for the purposes
+ * of determining uniqueness
+ */
+export function mergeIntoWith<T1, T2>(target: T1[], newItems: T1[], mergeWith: (item: T1) => T2) {
+  for (const item of newItems) {
+    const maybeItem = target.find((existingItem) => mergeWith(existingItem) === mergeWith(item));
+    if (!maybeItem) {
+      // this is a new item that isn't present in `target` yet
+      target.push(item);
+    }
+  }
+}
+
 /**
  * A utility for building an object from an iterable very similar to
  * `Object.fromEntries`

src/utils/test/helpers.spec.ts

@@ -1,4 +1,4 @@
-import { dashToPascalCase, isDef, isPromise, toCamelCase, toDashCase } from '../helpers';
+import { dashToPascalCase, isDef, isPromise, mergeIntoWith, toCamelCase, toDashCase } from '../helpers';
 
 describe('util helpers', () => {
   describe('isPromise', () => {
@@ -110,4 +110,31 @@ describe('util helpers', () => {
       expect(isDef(null)).toBe(false);
     });
   });
+
+  describe('mergeIntoWith', () => {
+    it('should do nothing if all elements already present', () => {
+      const target = [1, 2, 3];
+      mergeIntoWith(target, [1, 2, 3], (x) => x);
+      expect(target).toEqual([1, 2, 3]);
+    });
+
+    it('should add new items', () => {
+      const target = [1, 2, 3];
+      mergeIntoWith(target, [1, 2, 3, 4, 5], (x) => x);
+      expect(target).toEqual([1, 2, 3, 4, 5]);
+    });
+
+    it('should merge in objects using the predicate', () => {
+      const target = [{ id: 'foo' }, { id: 'bar' }, { id: 'boz' }, { id: 'baz' }];
+      mergeIntoWith(target, [{ id: 'foo' }, { id: 'fab' }, { id: 'fib' }], (x) => x.id);
+      expect(target).toEqual([
+        { id: 'foo' },
+        { id: 'bar' },
+        { id: 'boz' },
+        { id: 'baz' },
+        { id: 'fab' },
+        { id: 'fib' },
+      ]);
+    });
+  });
 });

test/docs-readme/package.json

@@ -0,0 +1,17 @@
+{
+  "name": "docs-readme-testbed",
+  "version": "1.0.0",
+  "description": "A test app for the docs-readme output target",
+  "files": [
+    "dist/"
+  ],
+  "scripts": {
+    "build": "node ../../bin/stencil build",
+    "build.dev": "node ../../bin/stencil build --dev",
+    "start": "node ../../bin/stencil build --dev --watch --serve",
+    "test": "node ../../bin/stencil test --spec --e2e",
+    "test.watch": "node ../../bin/stencil test --spec --e2e --watch",
+    "generate": "node ../../bin/stencil generate"
+  },
+  "license": "MIT"
+}

test/docs-readme/readme.md

@@ -0,0 +1,13 @@
+# docs-readme test app
+
+This directory contains a test application which exercises the `docs-readme`
+output target. This provides us with an end-to-end test of this functionality.
+
+## Components
+
+The components in here and what they test!
+
+### `<styleurls-component>`
+
+This tests that the docs from multiple `styleUrls` in the `@Component`
+decorator are pulled in to the docs output correctly.

test/docs-readme/src/components.d.ts

@@ -0,0 +1,37 @@
+/* eslint-disable */
+/* tslint:disable */
+/**
+ * This is an autogenerated file created by the Stencil compiler.
+ * It contains typing information for all components that exist in this project.
+ */
+import { HTMLStencilElement, JSXBase } from "@stencil/core/internal";
+export namespace Components {
+    interface StyleurlsComponent {
+    }
+}
+declare global {
+    interface HTMLStyleurlsComponentElement extends Components.StyleurlsComponent, HTMLStencilElement {
+    }
+    var HTMLStyleurlsComponentElement: {
+        prototype: HTMLStyleurlsComponentElement;
+        new (): HTMLStyleurlsComponentElement;
+    };
+    interface HTMLElementTagNameMap {
+        "styleurls-component": HTMLStyleurlsComponentElement;
+    }
+}
+declare namespace LocalJSX {
+    interface StyleurlsComponent {
+    }
+    interface IntrinsicElements {
+        "styleurls-component": StyleurlsComponent;
+    }
+}
+export { LocalJSX as JSX };
+declare module "@stencil/core" {
+    export namespace JSX {
+        interface IntrinsicElements {
+            "styleurls-component": LocalJSX.StyleurlsComponent & JSXBase.HTMLAttributes<HTMLStyleurlsComponentElement>;
+        }
+    }
+}

test/docs-readme/src/components/styleurls-component/one.scss

@@ -0,0 +1,6 @@
+:host {
+  /**
+   * @prop --one: Property One
+   */
+  display: block;
+}

test/docs-readme/src/components/styleurls-component/readme.md

@@ -0,0 +1,18 @@
+# styleurls-component
+
+
+
+<!-- Auto Generated Below -->
+
+
+## CSS Custom Properties
+
+| Name    | Description  |
+| ------- | ------------ |
+| `--one` | Property One |
+| `--two` | Property Two |
+
+
+----------------------------------------------
+
+*Built with [StencilJS](https://stenciljs.com/)*

test/docs-readme/src/components/styleurls-component/styleurls-component.tsx

@@ -0,0 +1,17 @@
+import { Component, h } from '@stencil/core';
+
+@Component({
+  tag: 'styleurls-component',
+  shadow: true,
+  // CSS properties documented in both of these files should
+  // show up in this component's README
+  styleUrls: {
+    one: 'one.scss',
+    two: 'two.scss',
+  },
+})
+export class StyleUrlsComponent {
+  render() {
+    return <div>Hello, World! I have multiple style URLs!</div>;
+  }
+}

test/docs-readme/src/components/styleurls-component/two.scss

@@ -0,0 +1,6 @@
+:host {
+  /**
+   * @prop --two: Property Two
+   */
+  display: block;
+}

test/docs-readme/src/index.html

@@ -0,0 +1,14 @@
+<!DOCTYPE html>
+<html dir="ltr" lang="en">
+  <head>
+    <meta charset="utf-8" />
+    <meta name="viewport" content="width=device-width, initial-scale=1.0, minimum-scale=1.0, maximum-scale=5.0" />
+    <title>Stencil Component Starter</title>
+
+    <script type="module" src="/build/json-docs-testbed.esm.js"></script>
+    <script nomodule src="/build/json-docs-testbed.js"></script>
+  </head>
+  <body>
+    <my-component first="Stencil" last="'Don't call me a framework' JS"></my-component>
+  </body>
+</html>

test/docs-readme/src/index.ts

@@ -0,0 +1 @@
+export * from './components';

test/docs-readme/stencil.config.ts

@@ -0,0 +1,13 @@
+import { Config } from '@stencil/core';
+
+export const config: Config = {
+  namespace: 'docs-readme-testbed',
+  outputTargets: [
+    {
+      type: 'docs-readme',
+    },
+    {
+      type: 'dist',
+    },
+  ],
+};

test/docs-readme/tsconfig.json

@@ -0,0 +1,40 @@
+{
+  "compilerOptions": {
+    "allowSyntheticDefaultImports": true,
+    "allowUnreachableCode": false,
+    "declaration": false,
+    "experimentalDecorators": true,
+    "lib": [
+      "dom",
+      "es2017"
+    ],
+    "moduleResolution": "node",
+    "module": "esnext",
+    "target": "es2017",
+    "noUnusedLocals": true,
+    "noUnusedParameters": true,
+    "jsx": "react",
+    "jsxFactory": "h",
+    "paths": {
+      "@stencil/core/testing": [
+        "../../src/testing/index.ts"
+      ],
+      "@stencil/core": [
+        "../../internal"
+      ],
+      "@stencil/core/compiler": [
+        "../../compiler"
+      ],
+      "@stencil/core/internal": [
+        "../../internal"
+      ]
+    }
+  },
+  "include": [
+    "src"
+  ],
+  "exclude": [
+    "node_modules"
+  ]
+
+}

test/package.json

@@ -5,15 +5,16 @@
     "TODO-STENCIL-389": "echo Remove the exit call below",
     "analysis": "exit 0 && node ./.scripts/analysis.js",
     "analysis.build-and-analyze": "npm run build && npm run analysis",
-    "build": "npm run build.browser-compile && npm run build.hello-world && npm run build.hello-vdom && npm run build.todo && npm run build.end-to-end && npm run build.ionic && npm run build.docs-json",
+    "build": "npm run build.browser-compile && npm run build.hello-world && npm run build.hello-vdom && npm run build.todo && npm run build.end-to-end && npm run build.ionic && npm run build.docs-json && npm run build.docs-readme",
     "bundlers": "cd ./bundler && npm run start",
     "build.browser-compile": "cd ./browser-compile && npm run build",
     "build.end-to-end": "cd ./end-to-end && npm ci && npm run build",
     "build.hello-world": "cd ./hello-world && npm run build",
     "build.hello-vdom": "cd ./hello-vdom && npm run build",
     "build.ionic": "cd ./ionic-app && npm ci && npm run build",
     "build.todo": "cd ./todo-app && npm ci && npm run build",
-    "build.docs-json": "cd ./docs-json && npm ci && npm run build"
+    "build.docs-json": "cd ./docs-json && npm ci && npm run build",
+    "build.docs-readme": "cd ./docs-readme && npm ci && npm run build"
   },
   "devDependencies": {
     "brotli": "^1.3.2"