Enable console color output by default

README.md

@@ -143,6 +143,10 @@ Some environment variables may be necessary for your particular case or to impro
 - DOTNET_CLI_TELEMETRY_OPTOUT - opt-out of telemetry being sent to Microsoft (default: false)
 - DOTNET_MULTILEVEL_LOOKUP - configures whether the global install location is used as a fall-back (default: true)
 
+**Note** Sets `DOTNET_SYSTEM_CONSOLE_ALLOW_ANSI_COLOR_REDIRECTION` and `TERM` to force color output by default (https://github.com/actions/setup-dotnet/issues/288).
+- DOTNET_SYSTEM_CONSOLE_ALLOW_ANSI_COLOR_REDIRECTION = true
+- TERM = xterm
+
 Example usage:
 ```yaml
 build:

dist/index.js

@@ -339,6 +339,10 @@ class DotnetCoreInstaller {
         }
         console.log(process.env['PATH']);
     }
+    static enableConsoleColorOutput() {
+        core.exportVariable('DOTNET_SYSTEM_CONSOLE_ALLOW_ANSI_COLOR_REDIRECTION', 'true');
+        core.exportVariable('TERM', 'xterm');
+    }
     // versionInfo - versionInfo of the SDK/Runtime
     resolveVersion(versionInfo) {
         return __awaiter(this, void 0, void 0, function* () {
@@ -486,6 +490,7 @@ function run() {
                     yield dotnetInstaller.installDotnet();
                 }
                 installer.DotnetCoreInstaller.addToPath();
+                installer.DotnetCoreInstaller.enableConsoleColorOutput();
             }
             const sourceUrl = core.getInput('source-url');
             const configFile = core.getInput('config-file');

src/installer.ts

@@ -197,6 +197,14 @@ export class DotnetCoreInstaller {
     console.log(process.env['PATH']);
   }
 
+  static enableConsoleColorOutput() {
+    core.exportVariable(
+      'DOTNET_SYSTEM_CONSOLE_ALLOW_ANSI_COLOR_REDIRECTION',
+      'true'
+    );
+    core.exportVariable('TERM', 'xterm');
+  }
+
   // versionInfo - versionInfo of the SDK/Runtime
   async resolveVersion(versionInfo: DotNetVersionInfo): Promise<string> {
     if (versionInfo.isExactVersion()) {

src/setup-dotnet.ts

@@ -50,6 +50,7 @@ export async function run() {
         await dotnetInstaller.installDotnet();
       }
       installer.DotnetCoreInstaller.addToPath();
+      installer.DotnetCoreInstaller.enableConsoleColorOutput();
     }
 
     const sourceUrl: string = core.getInput('source-url');