eslint[JSON]: Migrate to flat configuration model

Openbmc repo CI uses `eslint-plugin-json` package[1] for JSON linting,
and it appears that its broken for eslint@latest versions that mandated
the use of flat config. There is some on-going work on fixing the plugin
to add flat configuration support[2], but its still a work in progress.

This commits also removed `eslint-plugin-json` package and leverages
`eslint-plugin-jsonc` package[3], which is better maintained & also uses
the same AST as Javascript for linting.Since the plugin could provide
AST & source code text back to the eslint engine, we can now use eslint
directives such as `/*eslint-disable <checks>*/` in json files. Also it
does seem like there are plans to merge[4] `eslint-plugin-json` into
`eslint-plugin-jsonc`.

Flat configuration model deprecates the use of `.eslintrc.json` and also
`.eslintignore`. Instead eslint now relies on just one java script based
configuration file `eslint.config.mjs` for everything. So we had to now
add some logic into the configuration file to append the repo specific
ignores to the global ignores, which forced us to bring yet another
node js package `fs`. Since latest versions of eslint flags a warning if
there is a presence of deprecated `.eslintignore` file in repositories,I
renamed it from `.eslintignore` to `.eslintIgnore`.

[1]: https://www.npmjs.com/package/eslint-plugin-json
[2]: azeemba/eslint-plugin-json#82
[3]: https://www.npmjs.com/package/eslint-plugin-jsonc
[4]: azeemba/eslint-plugin-json#85

Change-Id: I0fa8c928a7449e08d761022dde1f1da3ee48cf62
Signed-off-by: Manojkiran Eda <manojkiran.eda@gmail.com>

config/eslint.config.mjs

@@ -0,0 +1,40 @@
+import eslintPluginJsonc from 'eslint-plugin-jsonc';
+import fs from 'fs';
+
+// Retrieve the default configuration
+const defaultConfig = eslintPluginJsonc.configs['flat/recommended-with-jsonc'];
+
+// Ensure defaultConfig.ignores is an array
+defaultConfig.ignores = defaultConfig.ignores || [];
+
+// Append additional ignore patterns to the default configuration
+const customConfig = [
+    ...defaultConfig,
+    {
+    ignores: [
+        ...defaultConfig.ignores,
+        "**/meson-*/*.json",
+        "subprojects/**/*.json"
+    ]}
+];
+
+try {
+    // Attempt to read the .eslintIgnore file
+    const eslintIgnoreContent = fs.readFileSync('.eslintIgnore', 'utf8');
+    // Split the content by new lines and remove empty lines
+    const ignorePatterns = eslintIgnoreContent.split('\n').filter(pattern => pattern.trim() !== '');
+    if (ignorePatterns.length > 0) {
+        // Ensure customConfig.ignores is an array
+        const ignoresIndex = customConfig.findIndex(obj => 'ignores' in obj);
+        if (ignoresIndex !== -1) {
+            customConfig[ignoresIndex].ignores = customConfig[ignoresIndex].ignores || [];
+            // Append the local ignores to the existing configuration
+            customConfig[ignoresIndex].ignores.push(...ignorePatterns);
+        }
+    }
+} catch (error) {
+    // Handle the case where the .eslintIgnore file is not present
+    console.info('\x1b[32m','Repo specific ignores are not present');
+}
+
+export default customConfig;

scripts/build-unit-test-docker

@@ -870,7 +870,8 @@ RUN pip3 install --break-system-packages \
         requests
 
 RUN npm install -g \
-        eslint@v8.56.0 eslint-plugin-json@latest \
+        eslint@latest eslint-plugin-jsonc@latest \
+        fs@latest \
         markdownlint-cli@latest \
         prettier@latest
 """

scripts/format-code.sh

@@ -197,14 +197,15 @@ function do_black() {
     black -l 79 "$@"
 }
 
-LINTER_REQUIRE+=([eslint]="eslint;.eslintrc.json;${CONFIG_PATH}/eslint-global-config.json")
-LINTER_IGNORE+=([eslint]=".eslintignore")
+LINTER_REQUIRE+=([eslint]="eslint;eslint.config.mjs;${CONFIG_PATH}/eslint.config.mjs")
+LINTER_IGNORE+=([eslint]=".eslintIgnore")
 LINTER_TYPES+=([eslint]="json")
 function do_eslint() {
-    eslint --no-eslintrc -c "${LINTER_CONFIG[eslint]}" \
-        --ext .json --format=stylish \
-        --resolve-plugins-relative-to /usr/local/lib/node_modules \
-        --no-error-on-unmatched-pattern "$@"
+    eslint --no-config-lookup --config "${LINTER_CONFIG[eslint]}" \
+	    --format=stylish \
+	    --color \
+	    --report-unused-disable-directives \
+	    --no-error-on-unmatched-pattern "$@"
 }
 
 LINTER_REQUIRE+=([flake8]="flake8")