feat: validate semantic version and refactor patch logic

- Added validation to `resolveKubectlVersion` to ensure input follows "major.minor" or "major.minor.patch" format.
- Moved `getLatestPatchVersion` from `run.ts` to `helpers.ts` to improve code organization and ensure a more robust testing process.

src/helpers.ts

@@ -1,6 +1,8 @@
 import * as os from 'os'
 import * as util from 'util'
-
+import * as fs from 'fs'
+import * as core from '@actions/core'
+import * as toolCache from '@actions/tool-cache'
 export function getKubectlArch(): string {
    const arch = os.arch()
    if (arch === 'x64') {
@@ -23,6 +25,29 @@ export function getkubectlDownloadURL(version: string, arch: string): string {
    }
 }
 
+export async function getLatestPatchVersion(
+   major: string,
+   minor: string
+): Promise<string> {
+   const sourceURL = `https://cdn.dl.k8s.io/release/stable-${major}.${minor}.txt`
+   try {
+      const downloadPath = await toolCache.downloadTool(sourceURL)
+      const latestPatch = fs
+         .readFileSync(downloadPath, 'utf8')
+         .toString()
+         .trim()
+      if (!latestPatch) {
+         throw new Error(`No patch version found for ${major}.${minor}`)
+      }
+      return latestPatch
+   } catch (error) {
+      core.debug(error)
+      core.warning('GetLatestPatchVersionFailed')
+      throw new Error(
+         `Failed to get latest patch version for ${major}.${minor}`
+      )
+   }
+}
 export function getExecutableExtension(): string {
    if (os.type().match(/^Win/)) {
       return '.exe'

src/run.test.ts

@@ -2,7 +2,8 @@ import * as run from './run'
 import {
    getkubectlDownloadURL,
    getKubectlArch,
-   getExecutableExtension
+   getExecutableExtension,
+   getLatestPatchVersion
 } from './helpers'
 import * as os from 'os'
 import * as toolCache from '@actions/tool-cache'
@@ -11,7 +12,11 @@ import * as path from 'path'
 import * as core from '@actions/core'
 import * as util from 'util'
 
+
 describe('Testing all functions in run file.', () => {
+   beforeEach(() => {
+      jest.clearAllMocks()
+   })
    test('getExecutableExtension() - return .exe when os is Windows', () => {
       jest.spyOn(os, 'type').mockReturnValue('Windows_NT')
       expect(getExecutableExtension()).toBe('.exe')
@@ -164,28 +169,27 @@ describe('Testing all functions in run file.', () => {
       )
       expect(toolCache.downloadTool).not.toHaveBeenCalled()
    })
-
    test('getLatestPatchVersion() - download and return latest patch version', async () => {
       jest
          .spyOn(toolCache, 'downloadTool')
-         .mockReturnValue(Promise.resolve('pathToTool'))
+         .mockResolvedValue('pathToTool')
       jest.spyOn(fs, 'readFileSync').mockReturnValue('v1.27.15')
 
-      const result = await run.getLatestPatchVersion('1', '27')
+      const result = await getLatestPatchVersion('1', '27')
 
       expect(result).toBe('v1.27.15')
       expect(toolCache.downloadTool).toHaveBeenCalledWith(
          'https://cdn.dl.k8s.io/release/stable-1.27.txt'
       )
-      expect(fs.readFileSync).toHaveBeenCalledWith('pathToTool', 'utf8')
    })
+
    test('getLatestPatchVersion() - throw error when patch version is empty', async () => {
       jest
          .spyOn(toolCache, 'downloadTool')
-         .mockReturnValue(Promise.resolve('pathToTool'))
+         .mockResolvedValue('pathToTool')
       jest.spyOn(fs, 'readFileSync').mockReturnValue('')
 
-      await expect(run.getLatestPatchVersion('1', '27')).rejects.toThrow(
+      await expect(getLatestPatchVersion('1', '27')).rejects.toThrow(
          'Failed to get latest patch version for 1.27'
       )
    })
@@ -195,35 +199,36 @@ describe('Testing all functions in run file.', () => {
          .spyOn(toolCache, 'downloadTool')
          .mockRejectedValue(new Error('Network error'))
 
-      await expect(run.getLatestPatchVersion('1', '27')).rejects.toThrow(
+      await expect(getLatestPatchVersion('1', '27')).rejects.toThrow(
          'Failed to get latest patch version for 1.27'
       )
    })
    test('resolveKubectlVersion() - expands major.minor to latest patch', async () => {
-      // Mock the getLatestPatchVersion call
-      jest.spyOn(run, 'getLatestPatchVersion').mockResolvedValue('v1.27.15')
+      jest
+         .spyOn(toolCache, 'downloadTool')
+         .mockResolvedValue('pathToTool')
+      jest.spyOn(fs, 'readFileSync').mockReturnValue('v1.27.15')
 
       const result = await run.resolveKubectlVersion('1.27')
-
       expect(result).toBe('v1.27.15')
-      expect(run.getLatestPatchVersion).toHaveBeenCalledWith('1', '27')
    })
+
    test('resolveKubectlVersion() - returns full version unchanged', async () => {
       const result = await run.resolveKubectlVersion('v1.27.15')
       expect(result).toBe('v1.27.15')
    })
-
    test('resolveKubectlVersion() - adds v prefix to full version', async () => {
       const result = await run.resolveKubectlVersion('1.27.15')
       expect(result).toBe('v1.27.15')
    })
    test('resolveKubectlVersion() - expands v-prefixed major.minor to latest patch', async () => {
-      jest.spyOn(run, 'getLatestPatchVersion').mockResolvedValue('v1.27.15')
+      jest
+         .spyOn(toolCache, 'downloadTool')
+         .mockResolvedValue('pathToTool')
+      jest.spyOn(fs, 'readFileSync').mockReturnValue('v1.27.15')
 
       const result = await run.resolveKubectlVersion('v1.27')
-
       expect(result).toBe('v1.27.15')
-      expect(run.getLatestPatchVersion).toHaveBeenCalledWith('1', '27')
    })
    test('run() - download specified version and set output', async () => {
       jest.spyOn(core, 'getInput').mockReturnValue('v1.15.5')

src/run.ts

@@ -1,14 +1,13 @@
 import * as path from 'path'
 import * as util from 'util'
 import * as fs from 'fs'
-import * as semver from 'semver'
 import * as toolCache from '@actions/tool-cache'
-import * as runModule from './run'
 import * as core from '@actions/core'
 import {
    getkubectlDownloadURL,
    getKubectlArch,
-   getExecutableExtension
+   getExecutableExtension,
+   getLatestPatchVersion
 } from './helpers'
 
 const kubectlToolName = 'kubectl'
@@ -92,43 +91,27 @@ export async function downloadKubectl(version: string): Promise<string> {
    return kubectlPath
 }
 
-export async function getLatestPatchVersion(
-   major: string,
-   minor: string
-): Promise<string> {
-   const sourceURL = `https://cdn.dl.k8s.io/release/stable-${major}.${minor}.txt`
-   try {
-      const downloadPath = await toolCache.downloadTool(sourceURL)
-      const latestPatch = fs
-         .readFileSync(downloadPath, 'utf8')
-         .toString()
-         .trim()
-      if (!latestPatch) {
-         throw new Error(`No patch version found for ${major}.${minor}`)
-      }
-      return latestPatch
-   } catch (error) {
-      core.debug(error)
-      core.warning('GetLatestPatchVersionFailed')
-      throw new Error(
-         `Failed to get latest patch version for ${major}.${minor}`
-      )
-   }
-}
-
 export async function resolveKubectlVersion(version: string): Promise<string> {
    const cleanedVersion = version.trim()
 
    /*------ detect "major.minor" only ----------------*/
    const mmMatch = cleanedVersion.match(/^v?(?<major>\d+)\.(?<minor>\d+)$/)
-   if (!mmMatch || !mmMatch.groups) {
-      // User already provided a full version such as 1.27.15 – do nothing.
+   if (mmMatch?.groups) {
+      const {major, minor} = mmMatch.groups
+      // Call the k8s CDN to get the latest patch version for the given major.minor
+      return await getLatestPatchVersion(major, minor)
+   }
+
+   /*------ detect "major.minor.patch" and validate ----------------*/
+   const mmpMatch = cleanedVersion.match(/^v?(\d+\.\d+\.\d+)$/)
+   if (!mmpMatch) {
+      throw new Error(
+         `Invalid version format: "${version}". Version must be in "major.minor" or "major.minor.patch" format (e.g., "1.27" or "v1.27.15").`
+      )
+   }
+
+   // User provided a full version such as 1.27.15, ensure it has a 'v' prefix.
    return cleanedVersion.startsWith('v')
       ? cleanedVersion
       : `v${cleanedVersion}`
-   }
-   const {major, minor} = mmMatch.groups
-
-   // Call the k8s CDN to get the latest patch version for the given major.minor
-   return await runModule.getLatestPatchVersion(major, minor)
 }