From 51d3b648af6db00f69c8fc12dc004efc982de2c8 Mon Sep 17 00:00:00 2001
From: Edoardo Cavazza <edoardo.cavazza@chialab.it>
Date: Fri, 15 Dec 2023 09:09:09 +0100
Subject: [PATCH] Support `stdin` manifest.

---
 .changeset/smart-humans-perform.md |  5 +++++
 src/cli.ts                         | 28 ++++++++++++++++++++++++----
 src/utils.ts                       | 17 ++++++++++++++++-
 3 files changed, 45 insertions(+), 5 deletions(-)
 create mode 100644 .changeset/smart-humans-perform.md

diff --git a/.changeset/smart-humans-perform.md b/.changeset/smart-humans-perform.md
new file mode 100644
index 0000000..0a5eb00
--- /dev/null
+++ b/.changeset/smart-humans-perform.md
@@ -0,0 +1,5 @@
+---
+'@chialab/plasma': minor
+---
+
+Support `stdin` manifest.
diff --git a/src/cli.ts b/src/cli.ts
index cf80adc..ce12884 100644
--- a/src/cli.ts
+++ b/src/cli.ts
@@ -8,7 +8,7 @@ import type { Package } from 'custom-elements-manifest';
 import { Listr } from 'listr2';
 import prompts from 'prompts';
 import { candidates, SUPPORTED, transform, UNSUPPORTED, type Frameworks } from './index';
-import { findJson } from './utils';
+import { findJson, validateManifest } from './utils';
 
 const colorFramework = (framework: string) => {
     switch (framework) {
@@ -29,6 +29,7 @@ const colorFramework = (framework: string) => {
 
 const packageJsonFile = fileURLToPath(new URL('../package.json', import.meta.url));
 const json = JSON.parse(await readFile(packageJsonFile, 'utf-8'));
+let stdin = '';
 
 program
     .name('plasma')
@@ -51,13 +52,20 @@ program
                 yes?: boolean;
             }
         ) => {
-            sourceDir = sourceDir ? resolve(sourceDir) : process.cwd();
+            let manifest: Package;
+            if (stdin) {
+                manifest = JSON.parse(stdin);
+            } else {
+                sourceDir = sourceDir ? resolve(sourceDir) : process.cwd();
 
-            const manifest = await findJson<Package>(sourceDir, 'custom-elements.json');
+                manifest = await findJson<Package>(sourceDir, 'custom-elements.json');
+            }
             if (!manifest) {
                 throw new Error('No custom elements manifest found');
             }
 
+            validateManifest(manifest);
+
             let entrypoint = options.entrypoint;
             if (!entrypoint) {
                 try {
@@ -181,4 +189,16 @@ program
         }
     );
 
-program.parse();
+if (process.stdin.isTTY) {
+    program.parse(process.argv);
+} else {
+    process.stdin.on('readable', () => {
+        let chunk: string;
+        while ((chunk = process.stdin.read()) !== null) {
+            stdin += chunk.toString();
+        }
+    });
+    process.stdin.on('end', () => {
+        program.parse(process.argv);
+    });
+}
diff --git a/src/utils.ts b/src/utils.ts
index ad4efdd..c94b9cc 100644
--- a/src/utils.ts
+++ b/src/utils.ts
@@ -1,6 +1,6 @@
 import { access, readFile } from 'node:fs/promises';
 import { dirname, extname, join } from 'node:path';
-import type { ClassField, CustomElementDeclaration } from 'custom-elements-manifest';
+import type { ClassField, CustomElementDeclaration, Package } from 'custom-elements-manifest';
 
 export function capitalize(str: string) {
     return str.charAt(0).toUpperCase() + str.slice(1);
@@ -57,3 +57,18 @@ export async function findJson<T = {}>(from: string, name: string) {
         return findJson(dir, name);
     }
 }
+
+export function validateManifest(manifest: Package) {
+    if (!manifest.schemaVersion) {
+        throw new Error('Malformed custom elements manifest: missing schemaVersion field');
+    }
+    if (typeof manifest.schemaVersion !== 'string') {
+        throw new Error('Malformed custom elements manifest: schemaVersion is not a string');
+    }
+    if (manifest.modules == null) {
+        throw new Error('Malformed custom elements manifest: missing modules field');
+    }
+    if (!Array.isArray(manifest.modules)) {
+        throw new Error('Malformed custom elements manifest: modules is not an array');
+    }
+}