Add .markdownlint.jsonc to list of automatically-used configuration files (with highest precedence for consistency with markdownlint-cli2) (fixes #290).

Author: DavidAnson

README.md

@@ -102,7 +102,7 @@ A sample configuration file:
 For more examples, see [.markdownlint.jsonc][markdownlint-jsonc], [.markdownlint.yaml][markdownlint-yaml], or the [style folder][style-folder].
 
 The CLI argument `--config` is not required.
-If it is not provided, `markdownlint-cli` looks for the file `.markdownlint.json`/`.markdownlint.yaml`/`.markdownlint.yml` in current folder, or for the file `.markdownlintrc` in the current or all parent folders.
+If it is not provided, `markdownlint-cli` looks for the file `.markdownlint.jsonc`/`.markdownlint.json`/`.markdownlint.yaml`/`.markdownlint.yml` in current folder, or for the file `.markdownlintrc` in the current or all parent folders.
 The algorithm is described in detail on the [`rc` package page][rc-standards].
 If the `--config` argument is provided, the file must be valid JSON, JSONC, JS, or YAML.
 JS configuration files contain JavaScript code, must have the `.js` or `.cjs` file extension, and must export (via `module.exports = ...`) a configuration object of the form shown above.

markdownlint.js

@@ -35,7 +35,7 @@ const exitCodes = {
   unexpectedError: 4
 };
 
-const projectConfigFiles = ['.markdownlint.json', '.markdownlint.yaml', '.markdownlint.yml'];
+const projectConfigFiles = ['.markdownlint.jsonc', '.markdownlint.json', '.markdownlint.yaml', '.markdownlint.yml'];
 const configFileParsers = [jsoncParse, jsYamlSafeLoad];
 const fsOptions = {encoding: 'utf8'};
 const processCwd = process.cwd();

test/config-files/jsonc/.markdownlint.json renamed to test/config-files/json-c/.markdownlint.json

@@ -0,0 +1,3 @@
+# Heading$
+
+Text

test/config-files/json-c/heading-dollar.md

@@ -0,0 +1,5 @@
+{
+  "no-trailing-punctuation": {
+    "punctuation": "!"
+  }
+}

test/config-files/jsonc-json-yaml-yml/.markdownlint.json

@@ -0,0 +1,5 @@
+{
+  "no-trailing-punctuation": {
+    "punctuation": "$"
+  }
+}

test/config-files/jsonc-json-yaml-yml/.markdownlint.jsonc

@@ -0,0 +1,2 @@
+no-trailing-punctuation:
+  punctuation: "!"

test/config-files/jsonc-json-yaml-yml/.markdownlint.yaml

@@ -0,0 +1,2 @@
+no-trailing-punctuation:
+  punctuation: "!"

test/config-files/jsonc-json-yaml-yml/.markdownlint.yml

@@ -0,0 +1,3 @@
+# Heading$
+
+Text

test/config-files/jsonc-json-yaml-yml/heading-dollar.md

@@ -0,0 +1,9 @@
+{
+  // Inline comment
+  "no-trailing-punctuation": {
+    /*
+     * Block comment
+     */
+    "punctuation": "$"
+  }
+}