Add sparse checkout support

src/git-command-manager.ts

@@ -38,6 +38,7 @@ export interface IGitCommandManager {
   revParse(ref: string): Promise<string>
   setEnvironmentVariable(name: string, value: string): void
   shaExists(sha: string): Promise<boolean>
+  sparseCheckout(cone: boolean, paths: string[]): Promise<void>
   submoduleForeach(command: string, recursive: boolean): Promise<string>
   submoduleSync(recursive: boolean): Promise<void>
   submoduleUpdate(fetchDepth: number, recursive: boolean): Promise<void>
@@ -292,6 +293,19 @@ class GitCommandManager {
     return output.exitCode === 0
   }
 
+  async sparseCheckout(cone: boolean, paths: string[]): Promise<void> {
+    const args1 = ['sparse-checkout', 'init']
+
+    if (cone) {
+      args1.push('--cone')
+    }
+
+    const args2 = ['sparse-checkout', 'set', '--', ...paths]
+
+    await this.execGit(args1)
+    await this.execGit(args2)
+  }
+
   async submoduleForeach(command: string, recursive: boolean): Promise<string> {
     const args = ['submodule', 'foreach']
     if (recursive) {

src/git-source-provider.ts

@@ -163,6 +163,13 @@ export async function getSource(settings: IGitSourceSettings): Promise<void> {
       core.endGroup()
     }
 
+    // Sparse checkout
+    if (settings.sparse) {
+      core.startGroup('Sparse checkout')
+      await git.sparseCheckout(settings.sparseCone, settings.sparse)
+      core.endGroup()
+    }
+
     // Checkout
     core.startGroup('Checking out the ref')
     await git.checkout(checkoutInfo.ref, checkoutInfo.startPoint)

src/git-source-settings.ts

@@ -78,4 +78,14 @@ export interface IGitSourceSettings {
    * Organization ID for the currently running workflow (used for auth settings)
    */
   workflowOrganizationId: number | undefined
+
+  /**
+   * Patterns to do a sparse checkout on
+   */
+  sparse: string[] | null
+
+  /**
+   * Whether or not to use cone pattern on sparse checkout
+   */
+  sparseCone: boolean
 }

src/input-helper.ts

@@ -93,6 +93,19 @@ export async function getInputs(): Promise<IGitSourceSettings> {
   result.lfs = (core.getInput('lfs') || 'false').toUpperCase() === 'TRUE'
   core.debug(`lfs = ${result.lfs}`)
 
+  if (core.getInput('sparse')) {
+    const paths = core
+      .getInput('sparse')
+      .trim()
+      .split(`\n`)
+      .map(s => s.trim())
+
+    result.sparse = paths
+  }
+
+  result.sparseCone =
+    (core.getInput('sparse-cone') || 'false').toUpperCase() === 'TRUE'
+
   // Submodules
   result.submodules = false
   result.nestedSubmodules = false