feat(migrate): more unsupported rule metadata for better clarity

.changeset/smooth-sites-sip.md

@@ -0,0 +1,5 @@
+---
+"@biomejs/biome": patch
+---
+
+Improved the summary provided by `biome migrate eslint` to be clearer on why rules were not migrated. Biome now specifies a reason when a rule is not migrated, such as being incompatible with the formatter or not implemented yet. This helps users make more informed decisions when migrating their ESLint configurations to Biome.

crates/biome_cli/src/execute/migrate.rs

@@ -36,6 +36,7 @@ mod eslint_unicorn;
 mod ignorefile;
 mod node;
 mod prettier;
+mod unsupported_rules;
 
 pub(crate) struct MigratePayload<'a> {
     pub(crate) session: CliSession<'a>,

crates/biome_cli/tests/commands/migrate_eslint.rs

@@ -712,3 +712,34 @@ fn migrate_merge_with_overrides() {
         result,
     ));
 }
+
+#[test]
+fn migrate_rules_covered_by_formatter() {
+    let biomejson = r#"{ "linter": { "enabled": true } }"#;
+    let eslintrc = r#"{
+        "rules": {
+            "eol-last": "error",
+            "indent": ["error", 2],
+        },
+    }"#;
+
+    let fs = MemoryFileSystem::default();
+    fs.insert(Utf8Path::new("biome.json").into(), biomejson.as_bytes());
+    fs.insert(Utf8Path::new(".eslintrc").into(), eslintrc.as_bytes());
+
+    let mut console = BufferConsole::default();
+    let (fs, result) = run_cli(
+        fs,
+        &mut console,
+        Args::from(["migrate", "eslint"].as_slice()),
+    );
+
+    assert!(result.is_ok(), "run_cli returned {result:?}");
+    assert_cli_snapshot(SnapshotPayload::new(
+        module_path!(),
+        "migrate_rules_covered_by_formatter",
+        fs,
+        console,
+        result,
+    ));
+}

crates/biome_cli/tests/snapshots/main_commands_migrate_eslint/migrate_eslint_config_packagejson.snap

@@ -49,7 +49,11 @@ biome.json migrate ━━━━━━━━━━━━━━━━━━━━
 ```block
 migrate ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
 
-  i 100% (1/1) of the rules can be migrated.
+  i 1 ESLint rules found
+    - 1 can be migrated to Biome's rules (run with --write to migrate)
+    - 100% (1) of your ESLint rules are fully covered by Biome
+      - 100% (1) via direct migration to Biome rules
+
 
 
 ```

crates/biome_cli/tests/snapshots/main_commands_migrate_eslint/migrate_eslintignore.snap

@@ -58,7 +58,11 @@ biome.json migrate ━━━━━━━━━━━━━━━━━━━━
 ```block
 migrate ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
 
-  i 100% (1/1) of the rules can be migrated.
+  i 1 ESLint rules found
+    - 1 can be migrated to Biome's rules (run with --write to migrate)
+    - 100% (1) of your ESLint rules are fully covered by Biome
+      - 100% (1) via direct migration to Biome rules
+
 
 
 ```

crates/biome_cli/tests/snapshots/main_commands_migrate_eslint/migrate_eslintignore_and_ignore_patterns.snap

@@ -56,7 +56,11 @@ biome.json migrate ━━━━━━━━━━━━━━━━━━━━
 ```block
 migrate ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
 
-  i 100% (1/1) of the rules can be migrated.
+  i 1 ESLint rules found
+    - 1 can be migrated to Biome's rules (run with --write to migrate)
+    - 100% (1) of your ESLint rules are fully covered by Biome
+      - 100% (1) via direct migration to Biome rules
+
 
 
 ```

crates/biome_cli/tests/snapshots/main_commands_migrate_eslint/migrate_eslintignore_negated_patterns.snap

@@ -49,7 +49,11 @@ biome.json migrate ━━━━━━━━━━━━━━━━━━━━
 ```block
 migrate ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
 
-  i 100% (1/1) of the rules can be migrated.
+  i 1 ESLint rules found
+    - 1 can be migrated to Biome's rules (run with --write to migrate)
+    - 100% (1) of your ESLint rules are fully covered by Biome
+      - 100% (1) via direct migration to Biome rules
+
 
 
 ```

crates/biome_cli/tests/snapshots/main_commands_migrate_eslint/migrate_eslintrc.snap

@@ -77,7 +77,11 @@ biome.json migrate ━━━━━━━━━━━━━━━━━━━━
 ```block
 migrate ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
 
-  i 100% (6/6) of the rules can be migrated.
+  i 6 ESLint rules found
+    - 6 can be migrated to Biome's rules (run with --write to migrate)
+    - 100% (6) of your ESLint rules are fully covered by Biome
+      - 100% (6) via direct migration to Biome rules
+
 
 
 ```

crates/biome_cli/tests/snapshots/main_commands_migrate_eslint/migrate_eslintrcjson.snap

@@ -77,7 +77,11 @@ biome.json migrate ━━━━━━━━━━━━━━━━━━━━
 ```block
 migrate ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
 
-  i 100% (6/6) of the rules can be migrated.
+  i 6 ESLint rules found
+    - 6 can be migrated to Biome's rules (run with --write to migrate)
+    - 100% (6) of your ESLint rules are fully covered by Biome
+      - 100% (6) via direct migration to Biome rules
+
 
 
 ```

crates/biome_cli/tests/snapshots/main_commands_migrate_eslint/migrate_eslintrcjson_exclude_inspired.snap

@@ -31,14 +31,17 @@ biome.json migrate ━━━━━━━━━━━━━━━━━━━━
 ```block
 migrate ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
 
-  i 100% (1/1) of the rules can be migrated.
+  i 1 ESLint rules found
+    - 0 can be migrated to Biome's rules (run with --write to migrate)
+      - +1 with --include-inspired
+    - 100% (1) of your ESLint rules are fully covered by Biome
+      - 0% (0) via direct migration to Biome rules
+
 
   i Rules that can be migrated to an inspired rule using --include-inspired:
 
   - no-else-return
 
-  i Rules that can be migrated to a nursery rule using --include-nursery:
-
 
 ```
 

crates/biome_cli/tests/snapshots/main_commands_migrate_eslint/migrate_eslintrcjson_extended_rules.snap

@@ -47,7 +47,11 @@ biome.json migrate ━━━━━━━━━━━━━━━━━━━━
 ```block
 migrate ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
 
-  i 100% (4/4) of the rules can be migrated.
+  i 4 ESLint rules found
+    - 4 can be migrated to Biome's rules (run with --write to migrate)
+    - 100% (4) of your ESLint rules are fully covered by Biome
+      - 100% (4) via direct migration to Biome rules
+
 
 
 ```

crates/biome_cli/tests/snapshots/main_commands_migrate_eslint/migrate_eslintrcjson_fix.snap

@@ -65,7 +65,11 @@ expression: redactor(content)
 ```block
 migrate ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
 
-  i 100% (6/6) of the rules have been migrated.
+  i 6 ESLint rules found
+    - 6 have been migrated to Biome's rules
+    - 100% (6) of your ESLint rules are fully covered by Biome
+      - 100% (6) via direct migration to Biome rules
+
 
 
 ```

crates/biome_cli/tests/snapshots/main_commands_migrate_eslint/migrate_eslintrcjson_include_inspired.snap

@@ -35,7 +35,11 @@ biome.json migrate ━━━━━━━━━━━━━━━━━━━━
 ```block
 migrate ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
 
-  i 100% (1/1) of the rules can be migrated.
+  i 1 ESLint rules found
+    - 1 can be migrated to Biome's rules (run with --write to migrate)
+    - 100% (1) of your ESLint rules are fully covered by Biome
+      - 100% (1) via direct migration to Biome rules
+
 
 
 ```

crates/biome_cli/tests/snapshots/main_commands_migrate_eslint/migrate_eslintrcjson_override_existing_config.snap

@@ -42,7 +42,11 @@ biome.json migrate ━━━━━━━━━━━━━━━━━━━━
 ```block
 migrate ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
 
-  i 100% (1/1) of the rules can be migrated.
+  i 1 ESLint rules found
+    - 1 can be migrated to Biome's rules (run with --write to migrate)
+    - 100% (1) of your ESLint rules are fully covered by Biome
+      - 100% (1) via direct migration to Biome rules
+
 
 
 ```

crates/biome_cli/tests/snapshots/main_commands_migrate_eslint/migrate_eslintrcjson_rule_options.snap

@@ -227,7 +227,11 @@ biome.json migrate ━━━━━━━━━━━━━━━━━━━━
 ```block
 migrate ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
 
-  i 100% (6/6) of the rules can be migrated.
+  i 6 ESLint rules found
+    - 6 can be migrated to Biome's rules (run with --write to migrate)
+    - 100% (6) of your ESLint rules are fully covered by Biome
+      - 100% (6) via direct migration to Biome rules
+
 
 
 ```

crates/biome_cli/tests/snapshots/main_commands_migrate_eslint/migrate_eslintrcjson_write.snap

@@ -65,7 +65,11 @@ expression: redactor(content)
 ```block
 migrate ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
 
-  i 100% (6/6) of the rules have been migrated.
+  i 6 ESLint rules found
+    - 6 have been migrated to Biome's rules
+    - 100% (6) of your ESLint rules are fully covered by Biome
+      - 100% (6) via direct migration to Biome rules
+
 
 
 ```

crates/biome_cli/tests/snapshots/main_commands_migrate_eslint/migrate_merge_with_overrides.snap

@@ -74,7 +74,11 @@ biome.json migrate ━━━━━━━━━━━━━━━━━━━━
 ```block
 migrate ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
 
-  i 100% (1/1) of the rules can be migrated.
+  i 1 ESLint rules found
+    - 1 can be migrated to Biome's rules (run with --write to migrate)
+    - 100% (1) of your ESLint rules are fully covered by Biome
+      - 100% (1) via direct migration to Biome rules
+
 
 
 ```

crates/biome_cli/tests/snapshots/main_commands_migrate_eslint/migrate_rules_covered_by_formatter.snap

@@ -0,0 +1,71 @@
+---
+source: crates/biome_cli/tests/snap_test.rs
+expression: redactor(content)
+---
+## `biome.json`
+
+```json
+{ "linter": { "enabled": true } }
+```
+
+## `.eslintrc`
+
+```eslintrc
+{
+        "rules": {
+            "eol-last": "error",
+            "indent": ["error", 2],
+        },
+    }
+```
+
+# Emitted Messages
+
+```block
+biome.json migrate ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
+
+  i Configuration file can be updated.
+
+    1   │ - {·"linter":·{·"enabled":·true·}·}
+      1 │ + {·"linter":·{·"enabled":·true,·"rules":·{·"recommended":·false·}·}·}
+      2 │ + 
+
+
+```
+
+```block
+migrate ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
+
+  i 2 ESLint rules found
+    - 2 are obsolete because of Biome's formatter
+    - 0 can be migrated to Biome's rules (run with --write to migrate)
+    - 100% (2) of your ESLint rules are fully covered by Biome
+      - 0% (0) via direct migration to Biome rules
+
+
+  i Unsupported rules (0 incompatible with formatter, 1 made obsolete by the formatter, 1 covered by a formatter option, 0 not yet implemented, 0 unknown source):
+
+  i These rules enforce behavior completely covered by the formatter (so you don't lose the functionality):
+
+  - eol-last
+
+  i These rules are covered by formatter options, but they require manual migration:
+
+  - indent - Covered by Biome's indentWidth formatter option.
+
+
+```
+
+```block
+configuration ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
+
+  i Migration results:
+
+  - biome.json: configuration needs migration.
+
+  i Use --write to apply the changes.
+
+  $ biome migrate --write
+
+
+```