add tests

Author: Mathiyarasy

src/test/preprocessPodman.test.ts

@@ -0,0 +1,120 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+import { assert } from 'chai';
+import * as fs from 'fs';
+import * as os from 'os';
+import * as path from 'path';
+import { ExecFunction, plainExec } from '../spec-common/commonUtils';
+import { nullLog } from '../spec-utils/log';
+import { ensureDockerfileHasFinalStageName, preprocessDockerfileIn } from '../spec-node/dockerfileUtils';
+
+describe('preprocessDockerfileIn', () => {
+    // Use the actual Dockerfile.in from the podman-with-cpp config directory.
+    // It defines BASE_IMAGE, INSTALL_NODE, and INSTALL_PYTHON macros, uses
+    // #ifdef/#endif blocks, and #includes common.Dockerfile and tools.Dockerfile.
+    const configDir = path.join(__dirname, 'configs', 'podman-with-cpp');
+    const dockerfileInPath = path.join(configDir, 'Dockerfile.in');
+
+    let tmpDir: string;
+
+    before(() => {
+        tmpDir = fs.mkdtempSync(path.join(os.tmpdir(), 'devcontainer-preprocess-test-'));
+    });
+
+    after(() => {
+        fs.rmSync(tmpDir, { recursive: true, force: true });
+    });
+
+    describe('when cpp is available on the host', () => {
+        let exec: ExecFunction;
+
+        before(async () => {
+            exec = await plainExec(undefined);
+        });
+
+        it('should preprocess #ifdef / #endif conditional blocks', async () => {
+            // INSTALL_NODE and INSTALL_PYTHON are both #define'd in Dockerfile.in
+            const result = await preprocessDockerfileIn(dockerfileInPath, exec, nullLog);
+
+            assert.include(result, 'apt-get install -y nodejs');
+            assert.include(result, 'apt-get install -y python3');
+            assert.notInclude(result, '#ifdef');
+            assert.notInclude(result, '#endif');
+        });
+
+        it('should inline content from #include directives', async () => {
+            // Dockerfile.in #includes common.Dockerfile and tools.Dockerfile
+            const result = await preprocessDockerfileIn(dockerfileInPath, exec, nullLog);
+
+            assert.include(result, 'apt-get install -y curl wget');
+            assert.include(result, 'APP_ENV=development');
+            assert.include(result, 'apt-get install -y vim');
+        });
+
+        it('should substitute macros and pass through plain Dockerfile content', async () => {
+            // BASE_IMAGE is #define'd as ubuntu:20.04 in Dockerfile.in
+            const result = await preprocessDockerfileIn(dockerfileInPath, exec, nullLog);
+
+            assert.include(result, 'FROM ubuntu:20.04');
+            assert.notInclude(result, 'FROM BASE_IMAGE');
+        });
+
+        it('should produce output parseable by ensureDockerfileHasFinalStageName when stage is unnamed', async () => {
+            // Dockerfile.in has no AS-named final stage, so a fallback name is assigned
+            const preprocessed = await preprocessDockerfileIn(dockerfileInPath, exec, nullLog);
+            const { lastStageName, modifiedDockerfile } = ensureDockerfileHasFinalStageName(preprocessed, 'dev');
+
+            assert.equal(lastStageName, 'dev');
+            assert.isDefined(modifiedDockerfile);
+        });
+
+        it('should produce output where ensureDockerfileHasFinalStageName assigns a name to an unnamed final stage', async () => {
+            // Dockerfile.in has no AS-named final stage, so the auto-generated label is injected
+            const preprocessed = await preprocessDockerfileIn(dockerfileInPath, exec, nullLog);
+            const { lastStageName, modifiedDockerfile } = ensureDockerfileHasFinalStageName(preprocessed, 'dev_container_auto_added_stage_label');
+
+            assert.equal(lastStageName, 'dev_container_auto_added_stage_label');
+            assert.isDefined(modifiedDockerfile);
+            assert.include(modifiedDockerfile!, 'AS dev_container_auto_added_stage_label');
+        });
+
+        it('should throw an error when the input file does not exist', async () => {
+            const nonExistentPath = path.join(tmpDir, 'does-not-exist.in');
+
+            let caughtError: Error | undefined;
+            try {
+                await preprocessDockerfileIn(nonExistentPath, exec, nullLog);
+            } catch (err: any) {
+                caughtError = err;
+            }
+
+            assert.isDefined(caughtError);
+            assert.include(caughtError!.message, 'Failed to preprocess');
+        });
+    });
+
+    describe('when cpp is not available on the host', () => {
+        // Simulate ENOENT by making exec throw with code 'ENOENT',
+        // mirroring what happens when the binary is missing.
+        const cppNotFoundExec: ExecFunction = async (_params) => {
+            const err: any = new Error('spawn cpp ENOENT');
+            err.code = 'ENOENT';
+            throw err;
+        };
+
+        it('should throw a clear error message directing the user to install cpp', async () => {
+            let caughtError: Error | undefined;
+            try {
+                await preprocessDockerfileIn(dockerfileInPath, cppNotFoundExec, nullLog);
+            } catch (err: any) {
+                caughtError = err;
+            }
+
+            assert.isDefined(caughtError);
+            assert.include(caughtError!.message, 'cpp');
+        });
+    });
+});