Fix #1745 - Throw on multiple configs (#1885)

This MR shows errors and exit in these conditions:

  * multiple `<py-config>` or `<mpy-config>` found on the page
  * both `<py-config>` and `<script type="py" config="file.toml">` found on main
  * different `<script type="py" config="a.toml">`  and `<script type="py" config="b.toml">` configs found on main

pyscript.core/package-lock.json

@@ -1,12 +1,12 @@
 {
     "name": "@pyscript/core",
-    "version": "0.3.7",
+    "version": "0.3.8",
     "lockfileVersion": 3,
     "requires": true,
     "packages": {
         "": {
             "name": "@pyscript/core",
-            "version": "0.3.7",
+            "version": "0.3.8",
             "license": "APACHE-2.0",
             "dependencies": {
                 "@ungap/with-resolvers": "^0.1.0",

pyscript.core/package.json

@@ -1,6 +1,6 @@
 {
     "name": "@pyscript/core",
-    "version": "0.3.7",
+    "version": "0.3.8",
     "type": "module",
     "description": "PyScript",
     "module": "./index.js",

pyscript.core/src/config.js

@@ -3,15 +3,17 @@
  * to use as base config for all py-script elements, importing
  * also a queue of plugins *before* the interpreter (if any) resolves.
  */
-import { $ } from "basic-devtools";
+import { $$ } from "basic-devtools";
 
 import TYPES from "./types.js";
 import allPlugins from "./plugins.js";
 import { robustFetch as fetch, getText } from "./fetch.js";
 import { ErrorCode } from "./exceptions.js";
 
+const { BAD_CONFIG, CONFLICTING_CODE } = ErrorCode;
+
 const badURL = (url, expected = "") => {
-    let message = `(${ErrorCode.BAD_CONFIG}): Invalid URL: ${url}`;
+    let message = `(${BAD_CONFIG}): Invalid URL: ${url}`;
     if (expected) message += `\nexpected ${expected} content`;
     throw new Error(message);
 };
@@ -41,8 +43,10 @@ const configDetails = async (config, type) => {
     return { json, toml: toml || (!json && !!text), text, url };
 };
 
+const conflictError = (reason) => new Error(`(${CONFLICTING_CODE}): ${reason}`);
+
 const syntaxError = (type, url, { message }) => {
-    let str = `(${ErrorCode.BAD_CONFIG}): Invalid ${type}`;
+    let str = `(${BAD_CONFIG}): Invalid ${type}`;
     if (url) str += ` @ ${url}`;
     return new SyntaxError(`${str}\n${message}`);
 };
@@ -56,27 +60,49 @@ for (const [TYPE] of TYPES) {
     /** @type {any} The PyScript configuration parsed from the JSON or TOML object*. May be any of the return types of JSON.parse() or toml-j0.4's parse() ( {number | string | boolean | null | object | Array} ) */
     let parsed;
 
-    /** @type {SyntaxError | undefined} The error thrown when parsing the PyScript config, if any.*/
+    /** @type {Error | undefined} The error thrown when parsing the PyScript config, if any.*/
     let error;
 
     let config,
         type,
-        pyConfig = $(`${TYPE}-config`);
+        pyElement,
-    if (pyConfig) {
+        pyConfigs = $$(`${TYPE}-config`),
-        config = pyConfig.getAttribute("src") || pyConfig.textContent;
+        attrConfigs = $$(
-        type = pyConfig.getAttribute("type");
-    } else {
-        pyConfig = $(
             [
                 `script[type="${TYPE}"][config]:not([worker])`,
                 `${TYPE}-script[config]:not([worker])`,
             ].join(","),
         );
-        if (pyConfig) config = pyConfig.getAttribute("config");
+
+    // throw an error if there are multiple <py-config> or <mpy-config>
+    if (pyConfigs.length > 1) {
+        error = conflictError(`Too many ${TYPE}-config`);
+    } else {
+        // throw an error if there are <x-config> and config="x" attributes
+        if (pyConfigs.length && attrConfigs.length) {
+            error = conflictError(
+                `Ambiguous ${TYPE}-config VS config attribute`,
+            );
+        } else if (pyConfigs.length) {
+            [pyElement] = pyConfigs;
+            config = pyElement.getAttribute("src") || pyElement.textContent;
+            type = pyElement.getAttribute("type");
+        } else if (attrConfigs.length) {
+            [pyElement, ...attrConfigs] = attrConfigs;
+            config = pyElement.getAttribute("config");
+            // throw an error if dirrent scripts use different configs
+            if (
+                attrConfigs.some((el) => el.getAttribute("config") !== config)
+            ) {
+                error = conflictError(
+                    "Unable to use different configs on main",
+                );
+            }
+        }
     }
 
     // catch possible fetch errors
-    if (config) {
+    if (!error && config) {
         try {
             const { json, toml, text, url } = await configDetails(config, type);
             config = text;

pyscript.core/test/config/ambiguous-config.html

@@ -0,0 +1,19 @@
+<!doctype html>
+<html lang="en">
+    <head>
+        <meta charset="UTF-8" />
+        <meta name="viewport" content="width=device-width, initial-scale=1.0" />
+        <title>PyScript Next</title>
+        <script>
+            addEventListener("error", ({ message }) => {
+                document.body.innerHTML += `<p>${message}</p>`;
+            });
+        </script>
+        <link rel="stylesheet" href="../../dist/core.css">
+        <script type="module" src="../../dist/core.js"></script>
+    </head>
+    <body>
+        <py-config>name = "first"</py-config>
+        <script type="py" config="second.toml"></script>
+    </body>
+</html>

pyscript.core/test/config/index.html

@@ -0,0 +1,16 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>Document</title>
+</head>
+<body>
+    <ul>
+        <li><a href="./ambiguous-config.html">ambiguous py-config VS config attribute</a></li>
+        <li><a href="./too-many-config.html">too many config attributes</a></li>
+        <li><a href="./too-many-py-config.html">too many &lt;py-config&gt;</a></li>
+        <li><a href="./same-config.html">same config attributes</a></li>
+    </ul>
+</body>
+</html>

pyscript.core/test/config/same-config.html

@@ -0,0 +1,20 @@
+<!doctype html>
+<html lang="en">
+    <head>
+        <meta charset="UTF-8" />
+        <meta name="viewport" content="width=device-width, initial-scale=1.0" />
+        <title>PyScript Next</title>
+        <script>
+            addEventListener("error", ({ message }) => {
+                document.body.innerHTML += `<p>${message}</p>`;
+            });
+        </script>
+        <link rel="stylesheet" href="../../dist/core.css">
+        <script type="module" src="../../dist/core.js"></script>
+    </head>
+    <body>
+        OK
+        <script type="py" config='{"name":"OK"}'></script>
+        <script type="py" config='{"name":"OK"}'></script>
+    </body>
+</html>

pyscript.core/test/config/too-many-config.html

@@ -0,0 +1,19 @@
+<!doctype html>
+<html lang="en">
+    <head>
+        <meta charset="UTF-8" />
+        <meta name="viewport" content="width=device-width, initial-scale=1.0" />
+        <title>PyScript Next</title>
+        <script>
+            addEventListener("error", ({ message }) => {
+                document.body.innerHTML += `<p>${message}</p>`;
+            });
+        </script>
+        <link rel="stylesheet" href="../../dist/core.css">
+        <script type="module" src="../../dist/core.js"></script>
+    </head>
+    <body>
+        <script type="py" config="first.toml"></script>
+        <script type="py" config="second.toml"></script>
+    </body>
+</html>

pyscript.core/test/config/too-many-py-config.html

@@ -0,0 +1,19 @@
+<!doctype html>
+<html lang="en">
+    <head>
+        <meta charset="UTF-8" />
+        <meta name="viewport" content="width=device-width, initial-scale=1.0" />
+        <title>PyScript Next</title>
+        <script>
+            addEventListener("error", ({ message }) => {
+                document.body.innerHTML += `<p>${message}</p>`;
+            });
+        </script>
+        <link rel="stylesheet" href="../../dist/core.css">
+        <script type="module" src="../../dist/core.js"></script>
+    </head>
+    <body>
+        <py-config>name = "first"</py-config>
+        <py-config>name = "second"</py-config>
+    </body>
+</html>

pyscript.core/tests/integration/test_py_config.py

@@ -100,7 +100,31 @@ class TestConfig(PyScriptTest):
         )
         assert banner.inner_text() == expected
 
-    @pytest.mark.skip("NEXT: emit a warning in case of multiple py-config")
+    def test_ambiguous_py_config(self):
+        self.pyscript_run(
+            """
+            <py-config>name = "first"</py-config>
+
+            <script type="py" config="second.toml"></script>
+            """,
+            wait_for_pyscript=False,
+        )
+        banner = self.page.wait_for_selector(".py-error")
+        expected = "(PY0409): Ambiguous py-config VS config attribute"
+        assert banner.text_content() == expected
+
+    def test_multiple_attributes_py_config(self):
+        self.pyscript_run(
+            """
+            <script type="py" config="first.toml"></script>
+            <script type="py" config="second.toml"></script>
+            """,
+            wait_for_pyscript=False,
+        )
+        banner = self.page.wait_for_selector(".py-error")
+        expected = "(PY0409): Unable to use different configs on main"
+        assert banner.text_content() == expected
+
     def test_multiple_py_config(self):
         self.pyscript_run(
             """
@@ -117,13 +141,11 @@ class TestConfig(PyScriptTest):
                 #config = js.pyscript_get_config()
                 #js.console.log("config name:", config.name)
             </script>
-            """
+            """,
-        )
+            wait_for_pyscript=False,
-        banner = self.page.wait_for_selector(".py-warning")
-        expected = (
-            "Multiple <py-config> tags detected. Only the first "
-            "is going to be parsed, all the others will be ignored"
         )
+        banner = self.page.wait_for_selector(".py-error")
+        expected = "(PY0409): Too many py-config"
         assert banner.text_content() == expected
 
     def test_paths(self):