diff --git a/packages/cli/src/index.ts b/packages/cli/src/index.ts
index 64421b8..258a62d 100644
--- a/packages/cli/src/index.ts
+++ b/packages/cli/src/index.ts
@@ -5,8 +5,8 @@ import * as path from 'node:path'
 import process from 'node:process'
 import { defineCommand } from 'citty'
 import { consola } from 'consola'
-import { name, version } from '../../toon/package.json' with { type: 'json' }
 import { DEFAULT_DELIMITER, DELIMITERS } from '../../toon/src'
+import { name, version } from '../package.json' with { type: 'json' }
 import { decodeToJson, encodeToToon } from './conversion'
 import { detectMode } from './utils'
 
diff --git a/packages/cli/test/index.test.ts b/packages/cli/test/index.test.ts
index bdae427..1bf9034 100644
--- a/packages/cli/test/index.test.ts
+++ b/packages/cli/test/index.test.ts
@@ -1,8 +1,8 @@
 import process from 'node:process'
 import { consola } from 'consola'
 import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest'
-import { version } from '../../toon/package.json' with { type: 'json' }
 import { DEFAULT_DELIMITER, encode } from '../../toon/src'
+import { version } from '../package.json' with { type: 'json' }
 import { createCliTestContext, runCli } from './utils'
 
 describe('toon CLI', () => {
@@ -14,113 +14,161 @@ describe('toon CLI', () => {
     vi.restoreAllMocks()
   })
 
-  it('prints the version when using --version', async () => {
-    const consolaLog = vi.spyOn(consola, 'log').mockImplementation(() => undefined)
-    const consolaError = vi.spyOn(consola, 'error').mockImplementation(() => undefined)
+  describe('version', () => {
+    it('prints the version when using --version', async () => {
+      const consolaLog = vi.spyOn(consola, 'log').mockImplementation(() => undefined)
 
-    await runCli({ rawArgs: ['--version'] })
+      await runCli({ rawArgs: ['--version'] })
 
-    expect(consolaLog).toHaveBeenCalledWith(version)
-    expect(consolaError).not.toHaveBeenCalled()
+      expect(consolaLog).toHaveBeenCalledWith(version)
+    })
   })
 
-  it('encodes a JSON file into a TOON file', async () => {
-    const data = {
-      title: 'TOON test',
-      count: 3,
-      nested: { ok: true },
-    }
-    const context = await createCliTestContext({
-      'input.json': JSON.stringify(data, undefined, 2),
-    })
-
-    const consolaSuccess = vi.spyOn(consola, 'success').mockImplementation(() => undefined)
-
-    try {
-      await context.run(['input.json', '--output', 'output.toon'])
-
-      const output = await context.read('output.toon')
-      const expected = encode(data, {
-        delimiter: DEFAULT_DELIMITER,
-        indent: 2,
-        lengthMarker: false,
+  describe('encode (JSON → TOON)', () => {
+    it('encodes a JSON file into a TOON file', async () => {
+      const data = {
+        title: 'TOON test',
+        count: 3,
+        nested: { ok: true },
+      }
+      const context = await createCliTestContext({
+        'input.json': JSON.stringify(data, undefined, 2),
       })
 
-      expect(output).toBe(expected)
-      expect(consolaSuccess).toHaveBeenCalledWith('Encoded `input.json` → `output.toon`')
-    }
-    finally {
-      await context.cleanup()
-    }
+      const consolaSuccess = vi.spyOn(consola, 'success').mockImplementation(() => undefined)
+
+      try {
+        await context.run(['input.json', '--output', 'output.toon'])
+
+        const output = await context.read('output.toon')
+        const expected = encode(data, {
+          delimiter: DEFAULT_DELIMITER,
+          indent: 2,
+          lengthMarker: false,
+        })
+
+        expect(output).toBe(expected)
+        expect(consolaSuccess).toHaveBeenCalledWith(expect.stringMatching(/Encoded .* → .*/))
+      }
+      finally {
+        await context.cleanup()
+      }
+    })
+
+    it('writes to stdout when output not specified', async () => {
+      const data = { ok: true }
+      const context = await createCliTestContext({
+        'input.json': JSON.stringify(data),
+      })
+
+      const stdout: string[] = []
+      const logSpy = vi.spyOn(console, 'log').mockImplementation((message?: unknown) => {
+        stdout.push(String(message ?? ''))
+      })
+
+      try {
+        await context.run(['input.json'])
+
+        expect(stdout).toHaveLength(1)
+        expect(stdout[0]).toBe(encode(data))
+      }
+      finally {
+        logSpy.mockRestore()
+        await context.cleanup()
+      }
+    })
   })
 
-  it('decodes a TOON file into a JSON file', async () => {
-    const data = {
-      items: ['alpha', 'beta'],
-      meta: { done: false },
-    }
-    const toonInput = encode(data)
-    const context = await createCliTestContext({
-      'input.toon': toonInput,
+  describe('decode (TOON → JSON)', () => {
+    it('decodes a TOON file into a JSON file', async () => {
+      const data = {
+        items: ['alpha', 'beta'],
+        meta: { done: false },
+      }
+      const toonInput = encode(data)
+      const context = await createCliTestContext({
+        'input.toon': toonInput,
+      })
+
+      const consolaSuccess = vi.spyOn(consola, 'success').mockImplementation(() => undefined)
+
+      try {
+        await context.run(['input.toon', '--output', 'output.json'])
+
+        const output = await context.read('output.json')
+        expect(JSON.parse(output)).toEqual(data)
+        expect(consolaSuccess).toHaveBeenCalledWith(expect.stringMatching(/Decoded .* → .*/))
+      }
+      finally {
+        await context.cleanup()
+      }
     })
-
-    const consolaSuccess = vi.spyOn(consola, 'success').mockImplementation(() => undefined)
-
-    try {
-      await context.run(['input.toon', '--output', 'output.json'])
-
-      const output = await context.read('output.json')
-      expect(JSON.parse(output)).toEqual(data)
-      expect(consolaSuccess).toHaveBeenCalledWith('Decoded `input.toon` → `output.json`')
-    }
-    finally {
-      await context.cleanup()
-    }
   })
 
-  it('writes encoded TOON to stdout when no output file is provided', async () => {
-    const data = { ok: true }
-    const context = await createCliTestContext({
-      'input.json': JSON.stringify(data),
+  describe('error handling', () => {
+    it('rejects invalid delimiter', async () => {
+      const context = await createCliTestContext({
+        'input.json': JSON.stringify({ value: 1 }),
+      })
+
+      const consolaError = vi.spyOn(consola, 'error').mockImplementation(() => undefined)
+      const exitSpy = vi.mocked(process.exit)
+
+      try {
+        await context.run(['input.json', '--delimiter', ';'])
+
+        expect(exitSpy).toHaveBeenCalledWith(1)
+
+        const errorCall = consolaError.mock.calls.at(0)
+        expect(errorCall).toBeDefined()
+        const [error] = errorCall!
+        expect(error).toBeInstanceOf(Error)
+        expect(error.message).toContain('Invalid delimiter')
+      }
+      finally {
+        await context.cleanup()
+      }
     })
 
-    const stdout: string[] = []
-    const logSpy = vi.spyOn(console, 'log').mockImplementation((message?: unknown) => {
-      stdout.push(String(message ?? ''))
+    it('rejects invalid indent value', async () => {
+      const context = await createCliTestContext({
+        'input.json': JSON.stringify({ value: 1 }),
+      })
+
+      const consolaError = vi.spyOn(consola, 'error').mockImplementation(() => undefined)
+      const exitSpy = vi.mocked(process.exit)
+
+      try {
+        await context.run(['input.json', '--indent', 'abc'])
+
+        expect(exitSpy).toHaveBeenCalledWith(1)
+
+        const errorCall = consolaError.mock.calls.at(0)
+        expect(errorCall).toBeDefined()
+        const [error] = errorCall!
+        expect(error).toBeInstanceOf(Error)
+        expect(error.message).toContain('Invalid indent value')
+      }
+      finally {
+        await context.cleanup()
+      }
     })
 
-    try {
-      await context.run(['input.json'])
+    it('handles missing input file', async () => {
+      const context = await createCliTestContext({})
 
-      expect(stdout).toHaveLength(1)
-      expect(stdout[0]).toBe(encode(data))
-    }
-    finally {
-      logSpy.mockRestore()
-      await context.cleanup()
-    }
-  })
+      const consolaError = vi.spyOn(consola, 'error').mockImplementation(() => undefined)
+      const exitSpy = vi.mocked(process.exit)
 
-  it('throws on an invalid delimiter argument', async () => {
-    const context = await createCliTestContext({
-      'input.json': JSON.stringify({ value: 1 }),
+      try {
+        await context.run(['nonexistent.json'])
+
+        expect(exitSpy).toHaveBeenCalledWith(1)
+        expect(consolaError).toHaveBeenCalled()
+      }
+      finally {
+        await context.cleanup()
+      }
     })
-
-    const consolaError = vi.spyOn(consola, 'error').mockImplementation(() => undefined)
-
-    try {
-      await expect(context.run(['input.json', '--delimiter', ';'])).resolves.toBeUndefined()
-
-      const exitMock = vi.mocked(process.exit)
-      expect(exitMock).toHaveBeenCalledWith(1)
-
-      const errorCall = consolaError.mock.calls.at(0)
-      expect(errorCall).toBeDefined()
-      const [error] = errorCall!
-      expect(error.message).toContain('Invalid delimiter')
-    }
-    finally {
-      await context.cleanup()
-    }
   })
 })