@@ -3,8 +3,10 @@ import path from "path"
 
 /**
  * Regular expression to match @ file references in text
+ * Matches @ followed by file paths, excluding commas, periods at end of sentences, and backticks
+ * Does not match when preceded by word characters or backticks (to avoid email addresses and quoted references)
  */
-export const fileRegex = /@([^\s]+)/g
+export const fileRegex = /(?<![\w`])@(\.?[^\s`,.]*(?:\.[^\s`,.]+)*)/g
 
 /**
  * File part type for chat input
@@ -32,7 +34,7 @@ export function processFileReferences(template: string, basePath: string): FileP
     const filename = match[1]
     const filepath = filename.startsWith("~/")
       ? path.join(os.homedir(), filename.slice(2))
-      : path.join(basePath, filename)
+      : path.resolve(basePath, filename)
 
     parts.push({
       type: "file",
 
@@ -0,0 +1,102 @@
+import { describe, expect, test, beforeAll, mock } from "bun:test"
+
+describe("processFileReferences", () => {
+  let result: any
+
+  beforeAll(async () => {
+    mock.module("os", () => ({ default: { homedir: () => "/home/fake-user" } }))
+    const { processFileReferences } = await import("../../src/session/file-reference")
+    const template = `This is a @valid/path/to/a/file and it should also match at
+the beginning of a line:
+
+@another-valid/path/to/a/file
+
+but this is not:
+
+   - Adds a "Co-authored-by:" footer which clarifies which AI agent
+     helped create this commit, using an appropriate \`noreply@...\`
+     or \`[email protected]\` email address.
+
+We also need to deal with files followed by @commas, ones
+with @file-extensions.md, even @multiple.extensions.bak,
+hidden directorys like @.config/ or files like @.bashrc
+and ones at the end of a sentence like @foo.md.
+
+Also shouldn't forget @/absolute/paths.txt with and @/without/extensions,
+as well as @~/home-files and @~/paths/under/home.txt.
+
+If the reference is \`@quoted/in/backticks\` then it shouldn't match at all.`
+    result = processFileReferences(template, "/base")
+  })
+
+  test("should extract exactly 12 file references", () => {
+    expect(result.length).toBe(12)
+  })
+
+  test("all files should have correct type and mime", () => {
+    result.forEach((file: any) => {
+      expect(file.type).toBe("file")
+      expect(file.mime).toBe("text/plain")
+    })
+  })
+
+  test("should extract valid/path/to/a/file", () => {
+    expect(result[0].filename).toBe("valid/path/to/a/file")
+    expect(result[0].url).toBe("file:///base/valid/path/to/a/file")
+  })
+
+  test("should extract another-valid/path/to/a/file", () => {
+    expect(result[1].filename).toBe("another-valid/path/to/a/file")
+    expect(result[1].url).toBe("file:///base/another-valid/path/to/a/file")
+  })
+
+  test("should extract paths ignoring comma after", () => {
+    expect(result[2].filename).toBe("commas")
+    expect(result[2].url).toBe("file:///base/commas")
+  })
+
+  test("should extract a path with a file extension and comma after", () => {
+    expect(result[3].filename).toBe("file-extensions.md")
+    expect(result[3].url).toBe("file:///base/file-extensions.md")
+  })
+
+  test("should extract a path with multiple dots and comma after", () => {
+    expect(result[4].filename).toBe("multiple.extensions.bak")
+    expect(result[4].url).toBe("file:///base/multiple.extensions.bak")
+  })
+
+  test("should extract hidden directory", () => {
+    expect(result[5].filename).toBe(".config/")
+    expect(result[5].url).toBe("file:///base/.config")
+  })
+
+  test("should extract hidden file", () => {
+    expect(result[6].filename).toBe(".bashrc")
+    expect(result[6].url).toBe("file:///base/.bashrc")
+  })
+
+  test("should extract a file ignoring period at end of sentence", () => {
+    expect(result[7].filename).toBe("foo.md")
+    expect(result[7].url).toBe("file:///base/foo.md")
+  })
+
+  test("should extract an absolute path with an extension", () => {
+    expect(result[8].filename).toBe("/absolute/paths.txt")
+    expect(result[8].url).toBe("file:///absolute/paths.txt")
+  })
+
+  test("should extract an absolute path without an extension", () => {
+    expect(result[9].filename).toBe("/without/extensions")
+    expect(result[9].url).toBe("file:///without/extensions")
+  })
+
+  test("should extract an absolute path in home directory", () => {
+    expect(result[10].filename).toBe("~/home-files")
+    expect(result[10].url).toBe("file:///home/fake-user/home-files")
+  })
+
+  test("should extract an absolute path under home directory", () => {
+    expect(result[11].filename).toBe("~/paths/under/home.txt")
+    expect(result[11].url).toBe("file:///home/fake-user/paths/under/home.txt")
+  })
+})