feat: change default ignore pattern to **/node_modules/ in flat config

docs/src/use/configure/configuration-files-new.md

@@ -143,7 +143,21 @@ export default [
 ];
 ```
 
-This configuration specifies that all of the files in the `.config` directory should be ignored. This pattern is added after the default patterns, which are `["**/node_modules/**", ".git/**"]`.
+This configuration specifies that all of the files in the `.config` directory should be ignored. This pattern is added after the default patterns, which are `["**/node_modules/", ".git/"]`.
+
+You can also unignore files and directories that are ignored by the default patterns. For example, this config unignores `node_modules/mylibrary`:
+
+```js
+export default [
+    {
+        ignores: [
+            "!node_modules/",           // unignore `node_modules/` directory
+            "node_modules/*",           // ignore its content
+            "!node_modules/mylibrary/"  // unignore `node_modules/mylibrary` directory
+        ]
+    }
+];
+```
 
 #### Cascading configuration objects
 

lib/config/default-config.js

@@ -48,7 +48,7 @@ exports.defaultConfig = [
     // default ignores are listed here
     {
         ignores: [
-            "**/node_modules/*",
+            "**/node_modules/",
             ".git/"
         ]
     },

lib/eslint/eslint-helpers.js

@@ -598,7 +598,7 @@ function createIgnoreResult(filePath, baseDir) {
     if (isHidden) {
         message = "File ignored by default.  Use a negated ignore pattern (like \"--ignore-pattern '!<relative/path/to/filename>'\") to override.";
     } else if (isInNodeModules) {
-        message = "File ignored by default. Use \"--ignore-pattern '!node_modules/*'\" to override.";
+        message = "File ignored by default because it is located under the node_modules directory. Use ignore pattern \"!**/node_modules/\" to override.";
     } else {
         message = "File ignored because of a matching ignore pattern. Use \"--no-ignore\" to override.";
     }

tests/lib/eslint/flat-eslint.js

@@ -661,7 +661,7 @@ describe("FlatESLint", () => {
                 ignore: false
             });
             const results = await eslint.lintText("var bar = foo;", { filePath: "node_modules/passing.js", warnIgnored: true });
-            const expectedMsg = "File ignored by default. Use \"--ignore-pattern '!node_modules/*'\" to override.";
+            const expectedMsg = "File ignored by default because it is located under the node_modules directory. Use ignore pattern \"!**/node_modules/\" to override.";
 
             assert.strictEqual(results.length, 1);
             assert.strictEqual(results[0].filePath, getFixturePath("node_modules/passing.js"));
@@ -1196,7 +1196,7 @@ describe("FlatESLint", () => {
                     cwd: getFixturePath("cli-engine")
                 });
                 const results = await eslint.lintFiles(["node_modules/foo.js"]);
-                const expectedMsg = "File ignored by default. Use \"--ignore-pattern '!node_modules/*'\" to override.";
+                const expectedMsg = "File ignored by default because it is located under the node_modules directory. Use ignore pattern \"!**/node_modules/\" to override.";
 
                 assert.strictEqual(results.length, 1);
                 assert.strictEqual(results[0].errorCount, 0);
@@ -3578,26 +3578,26 @@ describe("FlatESLint", () => {
                 assert(await engine.isPathIgnored(getFixturePath("ignored-paths", "subdir/node_modules/package/file.js")));
             });
 
-            it("should allow subfolders of defaultPatterns to be unignored by ignorePattern", async () => {
+            it("should allow subfolders of defaultPatterns to be unignored by ignorePattern constructor option", async () => {
                 const cwd = getFixturePath("ignored-paths");
                 const engine = new FlatESLint({
                     cwd,
                     overrideConfigFile: true,
-                    ignorePatterns: ["!node_modules/package/**"]
+                    ignorePatterns: ["!node_modules/", "node_modules/*", "!node_modules/package/"]
                 });
 
                 const result = await engine.isPathIgnored(getFixturePath("ignored-paths", "node_modules", "package", "file.js"));
 
                 assert(!result, "File should not be ignored");
             });
 
-            it("should allow subfolders of defaultPatterns to be unignored by ignorePath", async () => {
+            it("should allow subfolders of defaultPatterns to be unignored by ignores in overrideConfig", async () => {
                 const cwd = getFixturePath("ignored-paths");
                 const engine = new FlatESLint({
                     cwd,
                     overrideConfigFile: true,
                     overrideConfig: {
-                        ignores: ["!node_modules/package/**"]
+                        ignores: ["!node_modules/", "node_modules/*", "!node_modules/package/"]
                     }
                 });
 
@@ -4608,13 +4608,13 @@ describe("FlatESLint", () => {
         });
 
 
-        describe("ignores can unignore '/node_modules/foo'.", () => {
+        describe("ignores can unignore '/node_modules/foo' with patterns ['!node_modules/', 'node_modules/*', '!node_modules/foo/'].", () => {
 
             const { prepare, cleanup, getPath } = createCustomTeardown({
                 cwd: `${root}-unignores`,
                 files: {
                     "eslint.config.js": `module.exports = {
-                        ignores: ["!**/node_modules/foo"]
+                        ignores: ["!node_modules/", "node_modules/*", "!node_modules/foo/"]
                     };`,
                     "node_modules/foo/index.js": "",
                     "node_modules/foo/.dot.js": "",
@@ -4659,13 +4659,13 @@ describe("FlatESLint", () => {
             });
         });
 
-        describe("ignores can unignore '/node_modules/foo/**'.", () => {
+        describe("ignores can unignore '/node_modules/foo' with patterns ['!node_modules/', 'node_modules/*', '!node_modules/foo/**'].", () => {
 
             const { prepare, cleanup, getPath } = createCustomTeardown({
                 cwd: `${root}-unignores`,
                 files: {
                     "eslint.config.js": `module.exports = {
-                        ignores: ["!**/node_modules/foo/**"]
+                        ignores: ["!node_modules/", "node_modules/*", "!node_modules/foo/**"]
                     };`,
                     "node_modules/foo/index.js": "",
                     "node_modules/foo/.dot.js": "",
@@ -5093,7 +5093,7 @@ describe("FlatESLint", () => {
                             {
                                 ruleId: null,
                                 fatal: false,
-                                message: "File ignored by default. Use \"--ignore-pattern '!node_modules/*'\" to override.",
+                                message: "File ignored by default because it is located under the node_modules directory. Use ignore pattern \"!**/node_modules/\" to override.",
                                 severity: 1,
                                 nodeType: null
                             }
@@ -5194,7 +5194,7 @@ describe("FlatESLint", () => {
                 cwd: `${root}a3`,
                 files: {
                     "node_modules/myconf/eslint.config.js": `module.exports = [{
-                        ignores: ["!node_modules/myconf", "foo/*.js"],
+                        ignores: ["!node_modules", "node_modules/*", "!node_modules/myconf", "foo/*.js"],
                     }, {
                         rules: {
                             eqeqeq: "error"