Write screenshots to file. getgauge/gauge#1476

	- Change default and custome screenshot api <screenshotFn> to
          write screenshots to file.

	- Add a new API customScreenshotWriter

src/executor.js

@@ -67,9 +67,8 @@ var executeStep = function (executeStepRequest) {
       screenshotPromises.then(function (screenshots) {
         var errorResponse = factory.createExecutionStatusResponse(true, result.duration, result.exception, msgs, "", step.options.continueOnFailure, screenshots);
         if (process.env.screenshot_on_failure !== "false") {
-          screenshot.capture().then(function (bytes) {
-            errorResponse.executionResult.screenShot = bytes;
-            errorResponse.executionResult.failureScreenshot = bytes;
+          screenshot.capture().then(function (screenshotFile) {
+            errorResponse.executionResult.failureScreenshotFile = screenshotFile;
             deferred.reject(errorResponse);
           }).catch(function(error){
             logger.error("\nFailed to capture screenshot on failure.\n" + error);
@@ -116,9 +115,8 @@ var executeHook = function (hookLevel, currentExecutionInfo) {
   var onError = function (result) {
     var errorResponse = factory.createExecutionStatusResponse(true, result.duration, result.exception);
     if (process.env.screenshot_on_failure !== "false") {
-      screenshot.capture().then(function (bytes) {
-        errorResponse.executionResult.screenShot = bytes;
-        errorResponse.executionResult.failureScreenshot = bytes;
+      screenshot.capture().then(function (screenshotFile) {
+        errorResponse.executionResult.failureScreenshotFile = screenshotFile;
         deferred.reject(errorResponse);
       }).catch(function(error){
         logger.error("\nFailed to capture screenshot on failure.\n" + error);

src/gauge-global.js

@@ -44,6 +44,7 @@ gauge.message = function (msg) {
 };
 
 gauge.screenshotFn = null;
+gauge.customScreenshotWriter = null;
 
 gauge.step = function (stepName, options, stepFunction) {
   logger.error("[DEPRECATED] gauge.step() will be removed soon, use step() instead.");

src/message-processor.js

@@ -28,8 +28,8 @@ var processCustomMessages = function (response) {
 
 var processScreenshots = function (response) {
   var screenshotPromises = customScreenshotRegistry.get();
-  return screenshotPromises.then(function (screenshots) {
-    response.executionResult.screenshots = response.executionResult.screenshots.concat(screenshots);
+  return screenshotPromises.then(function (screenshotFiles) {
+    response.executionResult.screenshotFiles = response.executionResult.screenshotFiles.concat(screenshotFiles);
     customScreenshotRegistry.clear();
   });
 };

src/response-factory.js

@@ -70,7 +70,7 @@ exports.createStepValidateResponse = function (errorType, validated, suggestion)
   };
 };
 
-exports.createExecutionStatusResponse = function (isFailed, executionTime, err, msg, screenShot, recoverable, screenshots) {
+exports.createExecutionStatusResponse = function (isFailed, executionTime, err, msg, failureScreenshotFile, recoverable, screenshotFiles) {
   return {
     executionResult: {
       failed: isFailed,
@@ -79,9 +79,8 @@ exports.createExecutionStatusResponse = function (isFailed, executionTime, err,
       stackTrace: err && err.stack ? err.stack : "",
       errorMessage: err ? (err instanceof Error ? err.toString() : JSON.stringify(err)) : "",
       message: msg || [],
-      screenShot: screenShot || "",
-      failureScreenshot: screenShot || "",
-      screenshots: screenshots || []
+      failureScreenshotFile: failureScreenshotFile || "",
+      screenshotFiles: screenshotFiles || []
     }
   };
 

src/screenshot.js

@@ -1,35 +1,77 @@
-var os = require("os"),
-  path = require("path"),
+const path = require("path"),
   fs = require("fs"),
   child_process = require("child_process");
-var logger= require("./logger");
+var logger = require("./logger");
+const SCREENSHOTS_DIR_ENV = "gauge_screenshots_dir";
 
-var screenshot = function (tmpfile) {
-  tmpfile = tmpfile || path.join(os.tmpdir(), "screenshot-gauge-js-" + Date.now() + ".png");
-  var proc = child_process.spawnSync("gauge_screenshot", [tmpfile]);
-  if (proc.error) {
-    logger.error(proc.error.toString());
-    return "";
-  }
-  try {
-    return Buffer.from(fs.readFileSync(tmpfile)).toString("base64");
-  } catch (e) {
-    logger.info(e.toString());
-    return "";
-  }
+var defaultScreenshotWriter = function () {
+  return new Promise((resolve) => {
+    const filePath = getScreenshotFileName();
+    var proc = child_process.spawnSync("gauge_screenshot", [filePath]);
+    if (proc.error) {
+      logger.error(proc.error.toString());
+    }
+    resolve(path.basename(filePath));
+  });
 };
 
-function hasCustumScreenGrabber() {
-  return global.gauge && global.gauge.screenshotFn && typeof global.gauge.screenshotFn === "function";
+function getScreenshotFileName() {
+  return path.join(process.env[SCREENSHOTS_DIR_ENV], "screenshot-" + process.hrtime.bigint() + ".png");
 }
 
-function capture() {
-  var screenshotFn = hasCustumScreenGrabber() ? global.gauge.screenshotFn : screenshot;
-  var res = screenshotFn();
-  if (res instanceof Promise) {
-    return res;
+function isCustumScreenshotFun(funcName) {
+  return global.gauge && global.gauge[funcName] && typeof global.gauge[funcName] === "function";
+}
+
+function getScreenshotFunc() {
+  if (isCustumScreenshotFun("customScreenshotWriter")) {
+    return () => {
+      return new Promise((resolve) => {
+        const screenshotFile = global.gauge.customScreenshotWriter();
+        if (screenshotFile.constructor.name === "Promise") {
+          screenshotFile.then((file) => {
+            resolve(path.basename(file));
+          });
+        } else {
+          resolve(path.basename(screenshotFile));
+        }
+      });
+    };
+  } else if (isCustumScreenshotFun("screenshotFn")) {
+    return () => {
+      return new Promise((resolve) => {
+        logger.error("[DEPRECATED] gauge.screenshotFn will be removed soon, use gauge.customScreenshotWriter instead.");
+        const res = global.gauge.screenshotFn();
+        const screenshotFile = getScreenshotFileName();
+        if (res.constructor.name == "Promise") {
+          res.then((data) => {
+            errorHandling( () => {
+              fs.writeFileSync(screenshotFile, data);
+              resolve(path.basename(screenshotFile));
+            });
+          });
+        } else {
+          errorHandling( () => {
+            fs.writeFileSync(screenshotFile, res);
+            resolve(path.basename(screenshotFile));
+          });
+        }
+      });
+    };
   }
-  return Promise.resolve(res);
+  return defaultScreenshotWriter;
+}
+
+function errorHandling(action) {
+  try {
+    action();
+  } catch(e) {
+    logger.error(e);
+  }
+}
+function capture() {
+  var screenshotFn = getScreenshotFunc();
+  return screenshotFn();
 }
 
 module.exports = { capture: capture };

test/custom-screenshot-registry.js → test/custom-screenshot-registry-test.js

@@ -1,23 +1,23 @@
 var assert = require("chai").assert;
-var gauge = require("../src/gauge-global").gauge;
+var sandbox = require("sinon").createSandbox();
+var screenshot = require("../src/screenshot");
 var customScreenshotRegistry = require("../src/custom-screenshot-registry");
 
 describe("Custom Screenshot Registry", () => {
   beforeEach(() => {
-    gauge.screenshotFn = function () {
-      return "foo";
-    };
-    global.gauge = gauge;
+    sandbox.stub(screenshot, "capture")
+      .returns(Promise.resolve("screenshot-file.png"));
   });
 
   afterEach(() => {
+    sandbox.restore();
     customScreenshotRegistry.clear();
   });
 
   it("should add a screenshot", (done) => {
     customScreenshotRegistry.add();
     customScreenshotRegistry.get().then((screenshots) => {
-      assert.deepEqual(screenshots, ["foo"]);
+      assert.deepEqual(screenshots, ["screenshot-file.png"]);
       done();
     });
   });

test/executor-test.js

@@ -8,13 +8,15 @@ describe("Executing steps", function () {
   var executeStepRequest = null;
   var executeStepFailingRequest = null;
   this.timeout(10000);
+  var originalGlobalGauge;
 
   before(function () {
     var opts = { continueOnFailure: false };
     stepRegistry.clear();
     stepRegistry.add("Say <hi> to <me>", function () { }, "executor-test.js", 3, opts);
     stepRegistry.add("failing test", function () { throw new Error("error message"); }, "executor-test.js", 6, opts);
     sinon.spy(stepRegistry, "get");
+    originalGlobalGauge = global.gauge;
     global.gauge = {
       screenshotFn: function() {
         return Promise.resolve("screenshot");
@@ -37,6 +39,7 @@ describe("Executing steps", function () {
 
   after(function (done) {
     stepRegistry.get.restore();
+    global.gauge = originalGlobalGauge;
     done();
   });
 

test/screenshot-test.js

@@ -1,5 +1,8 @@
-var expect = require("chai").expect;
-var screenshot = require("../src/screenshot");
+const expect = require("chai").expect;
+const screenshot = require("../src/screenshot");
+const child_process = require("child_process");
+const fs = require("fs");
+const sandbox = require("sinon").createSandbox();
 
 
 function screenshotFunction() {
@@ -11,20 +14,87 @@ function asyncScreenshotFunction() {
 }
 
 describe("screentshot.capture", function () {
+  afterEach(() => {
+    sandbox.restore();
+  });
+  describe("with default screenshot writer", () => {
+    it("should capture screentshot 5769768", function (done) {
+      process.env.gauge_screenshots_dir = ".gauge/screenshots";
+      let screenShotFile = "screenshot-21432453.png";
+      const spawnSyncStub = sandbox.stub(child_process, "spawnSync").returns({});
+      sandbox.stub(process.hrtime, "bigint").returns(21432453);
+      screenshot.capture().then(function (file) {
+        const expectedArgs = ["gauge_screenshot", [".gauge/screenshots/" + screenShotFile]];
+        const actualArgs = spawnSyncStub.getCall(0).args;
+
+        expect(file).to.be.equal(screenShotFile);
+        expect(actualArgs).to.be.deep.equal(expectedArgs);
+        done();
+      });
+    });
+  });
+
+  describe("with custom screenshot grabber function", () => {
+    afterEach(function () {
+      global.gauge = { screenshotFn: null };
+    });
+    it("Should capture screentshot with async function", function (done) {
+      sandbox.stub(process.hrtime, "bigint").returns(6767787989089);
+      const screenShotFile = "screenshot-6767787989089.png";
+      global.gauge = { screenshotFn: asyncScreenshotFunction };
+      const writeFileSyncStub = sandbox.stub(fs, "writeFileSync");
+
+      screenshot.capture().then(function (file) {
+        const expectedArgs = [".gauge/screenshots/" + screenShotFile, Buffer.from("screentshot").toString("base64")];
+        const actualArgs = writeFileSyncStub.getCall(0).args;
+        expect(file).to.be.equal(screenShotFile);
+        expect(actualArgs).to.be.deep.equal(expectedArgs);
+        done();
+      });
+    });
+
+    it("Should capture screentshot with sync function", function (done) {
+      sandbox.stub(process.hrtime, "bigint").returns(6767787989089);
+      const screenShotFile = "screenshot-6767787989089.png";
+      global.gauge = { screenshotFn: screenshotFunction };
+      const writeFileSyncStub = sandbox.stub(fs, "writeFileSync");
 
-  it("Should capture screentshot and return base64 string", function (done) {
-    global.gauge = { screenshotFn: screenshotFunction };
-    screenshot.capture().then(function (bytes) {
-      expect(Buffer.from(bytes).toString(), "screentshot");
-      done();
+      screenshot.capture().then(function (file) {
+        const expectedArgs = [".gauge/screenshots/" + screenShotFile, Buffer.from("screentshot").toString("base64")];
+        const actualArgs = writeFileSyncStub.getCall(0).args;
+        expect(file).to.be.equal(screenShotFile);
+        expect(actualArgs).to.be.deep.equal(expectedArgs);
+        done();
+      });
     });
   });
 
-  it("Should capture screentshot with async custom screenshot function", function (done) {
-    global.gauge = { screenshotFn: asyncScreenshotFunction };
-    screenshot.capture().then(function (bytes) {
-      expect(Buffer.from(bytes).toString(), "screentshot");
-      done();
+  describe("with custom screenshot writer function", () => {
+    afterEach(() => {
+      global.gauge = { customScreenshotWriter: null };
+    });
+    it("Should capture screentshot with async function", function (done) {
+      const screenShotFile = "screenshot-file-1.png";
+      global.gauge = { customScreenshotWriter: function() {
+        return Promise.resolve(screenShotFile);
+      } };
+
+      screenshot.capture().then(function (file) {
+        expect(file).to.be.equal(screenShotFile);
+        done();
+      });
+    });
+
+    it("Should capture screentshot with sync function", function (done) {
+      const screenShotFile = "screenshot-file-2.png";
+      global.gauge = { customScreenshotWriter: function() {
+        return screenShotFile;
+      } };
+
+      screenshot.capture().then(function (file) {
+        expect(file).to.be.equal(screenShotFile);
+        done();
+      });
     });
   });
 });