diff --git a/crates/biome_formatter_test/src/spec.rs b/crates/biome_formatter_test/src/spec.rs
index edf0c32c6676..a389314d3b17 100644
--- a/crates/biome_formatter_test/src/spec.rs
+++ b/crates/biome_formatter_test/src/spec.rs
@@ -11,7 +11,9 @@ use biome_fs::BiomePath;
 use biome_parser::AnyParse;
 use biome_rowan::{TextRange, TextSize};
 use biome_service::settings::{ServiceLanguage, Settings};
-use biome_service::workspace::{DocumentFileSource, FeaturesBuilder, SupportsFeatureParams};
+use biome_service::workspace::{
+    DocumentFileSource, FeaturesBuilder, RegisterProjectFolderParams, SupportsFeatureParams,
+};
 use biome_service::App;
 use std::ops::Range;
 use std::path::{Path, PathBuf};
@@ -40,6 +42,12 @@ impl<'a> SpecTestFile<'a> {
             spec_input_file.display()
         );
 
+        app.workspace
+            .register_project_folder(RegisterProjectFolderParams {
+                set_as_current_workspace: true,
+                path: None,
+            })
+            .unwrap();
         let mut input_file = BiomePath::new(file_path);
         let can_format = app
             .workspace
diff --git a/crates/biome_service/tests/workspace.rs b/crates/biome_service/tests/workspace.rs
index 8623f3c92678..7250cb393dc8 100644
--- a/crates/biome_service/tests/workspace.rs
+++ b/crates/biome_service/tests/workspace.rs
@@ -1,162 +1,176 @@
-use biome_fs::BiomePath;
-use biome_js_syntax::{JsFileSource, TextSize};
-use biome_service::file_handlers::DocumentFileSource;
-use biome_service::workspace::{server, FileGuard, OpenFileParams};
-
-#[test]
-fn debug_control_flow() {
-    const SOURCE: &str = "function test () { return; }";
-    const GRAPH: &str = "flowchart TB
-    block_0[\"<b>block_0</b><br/>Return(JS_RETURN_STATEMENT 19..26)<br/>Return\"]
-
-";
-
-    let workspace = server();
-
-    let file = FileGuard::open(
-        workspace.as_ref(),
-        OpenFileParams {
-            path: BiomePath::new("file.js"),
-            content: SOURCE.into(),
-            version: 0,
-            document_file_source: Some(DocumentFileSource::from(JsFileSource::default())),
-        },
-    )
-    .unwrap();
-
-    let cfg = file.get_control_flow_graph(TextSize::from(20)).unwrap();
-
-    assert_eq!(cfg, GRAPH);
-}
-
-#[test]
-fn recognize_typescript_definition_file() {
-    let workspace = server();
-
-    let file = FileGuard::open(
-        workspace.as_ref(),
-        OpenFileParams {
-            path: BiomePath::new("file.d.ts"),
-            // the following code snippet can be correctly parsed in .d.ts file but not in .ts file
-            content: "export const foo: number".into(),
-            version: 0,
-            document_file_source: None,
-        },
-    )
-    .unwrap();
-
-    assert!(file.format_file().is_ok());
-}
-
-#[test]
-fn correctly_handle_json_files() {
-    let workspace = server();
-
-    // ".json" file
-    let json_file = FileGuard::open(
-        workspace.as_ref(),
-        OpenFileParams {
-            path: BiomePath::new("a.json"),
-            content: r#"{"a": 42}"#.into(),
-            version: 0,
-            document_file_source: None,
-        },
-    )
-    .unwrap();
-    assert!(json_file.format_file().is_ok());
-
-    // ".json" file doesn't allow comments
-    let json_file_with_comments = FileGuard::open(
-        workspace.as_ref(),
-        OpenFileParams {
-            path: BiomePath::new("b.json"),
-            content: r#"{"a": 42}//comment"#.into(),
-            version: 0,
-            document_file_source: None,
-        },
-    )
-    .unwrap();
-    assert!(json_file_with_comments.format_file().is_err());
-
-    // ".json" file doesn't allow trailing commas
-    let json_file_with_trailing_commas = FileGuard::open(
-        workspace.as_ref(),
-        OpenFileParams {
-            path: BiomePath::new("c.json"),
-            content: r#"{"a": 42,}"#.into(),
-            version: 0,
-            document_file_source: None,
-        },
-    )
-    .unwrap();
-    assert!(json_file_with_trailing_commas.format_file().is_err());
-
-    // ".jsonc" file allows comments
-    let jsonc_file = FileGuard::open(
-        workspace.as_ref(),
-        OpenFileParams {
-            path: BiomePath::new("d.jsonc"),
-            content: r#"{"a": 42}//comment"#.into(),
-            version: 0,
-            document_file_source: None,
-        },
-    )
-    .unwrap();
-    assert!(jsonc_file.format_file().is_ok());
-
-    // ".jsonc" file allow trailing commas
-    let jsonc_file = FileGuard::open(
-        workspace.as_ref(),
-        OpenFileParams {
-            path: BiomePath::new("e.jsonc"),
-            content: r#"{"a": 42,}"#.into(),
-            version: 0,
-            document_file_source: None,
-        },
-    )
-    .unwrap();
-    assert!(jsonc_file.format_file().is_ok());
-
-    // well-known json-with-comments file allows comments
-    let well_known_json_with_comments_file = FileGuard::open(
-        workspace.as_ref(),
-        OpenFileParams {
-            path: BiomePath::new(".eslintrc.json"),
-            content: r#"{"a": 42}//comment"#.into(),
-            version: 0,
-            document_file_source: None,
-        },
-    )
-    .unwrap();
-    assert!(well_known_json_with_comments_file.format_file().is_ok());
-
-    // well-known json-with-comments file doesn't allow trailing commas
-    let well_known_json_with_comments_file_with_trailing_commas = FileGuard::open(
-        workspace.as_ref(),
-        OpenFileParams {
-            path: BiomePath::new("dir/.eslintrc.json"),
-            content: r#"{"a": 42,}"#.into(),
-            version: 0,
-            document_file_source: None,
-        },
-    )
-    .unwrap();
-    assert!(well_known_json_with_comments_file_with_trailing_commas
-        .format_file()
-        .is_err());
-
-    // well-known json-with-comments-and-trailing-commas file allows comments and trailing commas
-    let well_known_json_with_comments_and_trailing_commas_file = FileGuard::open(
-        workspace.as_ref(),
-        OpenFileParams {
-            path: BiomePath::new("tsconfig.json"),
-            content: r#"{"a": 42,}//comment"#.into(),
-            version: 0,
-            document_file_source: None,
-        },
-    )
-    .unwrap();
-    assert!(well_known_json_with_comments_and_trailing_commas_file
-        .format_file()
-        .is_ok());
+#[cfg(test)]
+mod test {
+    use biome_fs::BiomePath;
+    use biome_js_syntax::{JsFileSource, TextSize};
+    use biome_service::file_handlers::DocumentFileSource;
+    use biome_service::workspace::{
+        server, FileGuard, OpenFileParams, RegisterProjectFolderParams,
+    };
+    use biome_service::Workspace;
+    fn create_server() -> Box<dyn Workspace> {
+        let workspace = server();
+        workspace
+            .register_project_folder(RegisterProjectFolderParams {
+                set_as_current_workspace: true,
+                path: None,
+            })
+            .unwrap();
+
+        workspace
+    }
+
+    #[test]
+    fn debug_control_flow() {
+        const SOURCE: &str = "function test () { return; }";
+        const GRAPH: &str = "flowchart TB
+    block_0[\"<b>block_0</b><br/>Return(JS_RETURN_STATEMENT 19..26)<br/>Return\"]\n\n";
+
+        let workspace = create_server();
+        let file = FileGuard::open(
+            workspace.as_ref(),
+            OpenFileParams {
+                path: BiomePath::new("file.js"),
+                content: SOURCE.into(),
+                version: 0,
+                document_file_source: Some(DocumentFileSource::from(JsFileSource::default())),
+            },
+        )
+        .unwrap();
+
+        let cfg = file.get_control_flow_graph(TextSize::from(20)).unwrap();
+
+        assert_eq!(cfg, GRAPH);
+    }
+
+    #[test]
+    fn recognize_typescript_definition_file() {
+        let workspace = create_server();
+
+        let file = FileGuard::open(
+            workspace.as_ref(),
+            OpenFileParams {
+                path: BiomePath::new("file.d.ts"),
+                // the following code snippet can be correctly parsed in .d.ts file but not in .ts file
+                content: "export const foo: number".into(),
+                version: 0,
+                document_file_source: None,
+            },
+        )
+        .unwrap();
+
+        assert!(file.format_file().is_ok());
+    }
+
+    #[test]
+    fn correctly_handle_json_files() {
+        let workspace = create_server();
+
+        // ".json" file
+        let json_file = FileGuard::open(
+            workspace.as_ref(),
+            OpenFileParams {
+                path: BiomePath::new("a.json"),
+                content: r#"{"a": 42}"#.into(),
+                version: 0,
+                document_file_source: None,
+            },
+        )
+        .unwrap();
+        assert!(json_file.format_file().is_ok());
+
+        // ".json" file doesn't allow comments
+        let json_file_with_comments = FileGuard::open(
+            workspace.as_ref(),
+            OpenFileParams {
+                path: BiomePath::new("b.json"),
+                content: r#"{"a": 42}//comment"#.into(),
+                version: 0,
+                document_file_source: None,
+            },
+        )
+        .unwrap();
+        assert!(json_file_with_comments.format_file().is_err());
+
+        // ".json" file doesn't allow trailing commas
+        let json_file_with_trailing_commas = FileGuard::open(
+            workspace.as_ref(),
+            OpenFileParams {
+                path: BiomePath::new("c.json"),
+                content: r#"{"a": 42,}"#.into(),
+                version: 0,
+                document_file_source: None,
+            },
+        )
+        .unwrap();
+        assert!(json_file_with_trailing_commas.format_file().is_err());
+
+        // ".jsonc" file allows comments
+        let jsonc_file = FileGuard::open(
+            workspace.as_ref(),
+            OpenFileParams {
+                path: BiomePath::new("d.jsonc"),
+                content: r#"{"a": 42}//comment"#.into(),
+                version: 0,
+                document_file_source: None,
+            },
+        )
+        .unwrap();
+        assert!(jsonc_file.format_file().is_ok());
+
+        // ".jsonc" file allow trailing commas
+        let jsonc_file = FileGuard::open(
+            workspace.as_ref(),
+            OpenFileParams {
+                path: BiomePath::new("e.jsonc"),
+                content: r#"{"a": 42,}"#.into(),
+                version: 0,
+                document_file_source: None,
+            },
+        )
+        .unwrap();
+        assert!(jsonc_file.format_file().is_ok());
+
+        // well-known json-with-comments file allows comments
+        let well_known_json_with_comments_file = FileGuard::open(
+            workspace.as_ref(),
+            OpenFileParams {
+                path: BiomePath::new(".eslintrc.json"),
+                content: r#"{"a": 42}//comment"#.into(),
+                version: 0,
+                document_file_source: None,
+            },
+        )
+        .unwrap();
+        assert!(well_known_json_with_comments_file.format_file().is_ok());
+
+        // well-known json-with-comments file doesn't allow trailing commas
+        let well_known_json_with_comments_file_with_trailing_commas = FileGuard::open(
+            workspace.as_ref(),
+            OpenFileParams {
+                path: BiomePath::new("dir/.eslintrc.json"),
+                content: r#"{"a": 42,}"#.into(),
+                version: 0,
+                document_file_source: None,
+            },
+        )
+        .unwrap();
+        assert!(well_known_json_with_comments_file_with_trailing_commas
+            .format_file()
+            .is_err());
+
+        // well-known json-with-comments-and-trailing-commas file allows comments and trailing commas
+        let well_known_json_with_comments_and_trailing_commas_file = FileGuard::open(
+            workspace.as_ref(),
+            OpenFileParams {
+                path: BiomePath::new("tsconfig.json"),
+                content: r#"{"a": 42,}//comment"#.into(),
+                version: 0,
+                document_file_source: None,
+            },
+        )
+        .unwrap();
+        assert!(well_known_json_with_comments_and_trailing_commas_file
+            .format_file()
+            .is_ok());
+    }
 }
diff --git a/packages/@biomejs/backend-jsonrpc/tests/workspace.test.mjs b/packages/@biomejs/backend-jsonrpc/tests/workspace.test.mjs
index 0b28f79b74e7..38e7d461e1e1 100644
--- a/packages/@biomejs/backend-jsonrpc/tests/workspace.test.mjs
+++ b/packages/@biomejs/backend-jsonrpc/tests/workspace.test.mjs
@@ -1,8 +1,8 @@
-import { resolve } from "node:path";
-import { fileURLToPath } from "node:url";
-import { describe, expect, it } from "vitest";
+import {resolve} from "node:path";
+import {fileURLToPath} from "node:url";
+import {describe, expect, it} from "vitest";
 
-import { createWorkspaceWithBinary } from "../dist/index.js";
+import {createWorkspaceWithBinary} from "../dist/index.js";
 
 describe("Workspace API", () => {
 	it("should process remote requests", async () => {
@@ -14,7 +14,9 @@ describe("Workspace API", () => {
 		);
 
 		const workspace = await createWorkspaceWithBinary(command);
-
+		workspace.registerProjectFolder({
+			setAsCurrentWorkspace: true
+		});
 		await workspace.openFile({
 			path: {
 				path: "test.js",