[#1659] Separate backend and frontend responsibilites (#1691)

The backend modifies files generated by the frontend. This breaks the
separation of responsibilities for generated report files, which makes 
testing more challenging.

Let's stop the backend manually modifying report titles in frontend
generated files, and have the frontend update the report title itself. 
The default report title generated by the frontend is now also 
'RepoSense Report' instead of 'reposense' so that there is no delay in
updating the report title in the default case. The backend will proceed
to generate report files in the absence of `templateZip.zip`. Let's
also add a test to check that report titles are correctly updated.

build.gradle

@@ -158,7 +158,7 @@ task systemtest(dependsOn: 'zipReport', type: Test) {
 task startServerInBackground(dependsOn: 'classes', type: com.github.psxpaul.task.JavaExecFork) {
     main = mainClassName
     classpath = sourceSets.main.runtimeClasspath
-    args = ['--repo', 'https://github.com/reposense/RepoSense.git', 'https://github.com/reposense/testrepo-Empty.git', '--since', 'd1', '--view']
+    args = ['--config', './frontend/cypress/config', '--since', 'd1', '--view']
     String versionJvmArgs = '-Dversion=' + getRepoSenseVersion()
     jvmArgs = [ versionJvmArgs ]
     waitForPort = 9000

frontend/cypress/config/repo-config.csv

@@ -0,0 +1,3 @@
+Repository's Location,Branch,File formats,Ignore Glob List,Ignore standalone config,Ignore Commits List,Ignore Authors List,Shallow Cloning,Find Previous Authors
+https://github.com/reposense/RepoSense.git,master,,,,,,,
+https://github.com/reposense/testrepo-Empty.git,master,,,,,,,

frontend/cypress/config/report-config.json

@@ -0,0 +1,3 @@
+{
+  "title": "RepoSense Test Report"
+}

frontend/cypress/tests/general/general.js

@@ -0,0 +1,5 @@
+describe('general', () => {
+  it('correctly replaces report title', () => {
+    cy.title().should('eq', 'RepoSense Test Report');
+  });
+});

frontend/src/utils/api.js

@@ -183,6 +183,7 @@ window.api = {
     window.repoSenseVersion = data.repoSenseVersion;
     window.isSinceDateProvided = data.isSinceDateProvided;
     window.isUntilDateProvided = data.isUntilDateProvided;
+    document.title = data.reportTitle || document.title;
 
     const errorMessages = {};
     Object.entries(data.errorSet).forEach(([repoName, message]) => {

frontend/vue.config.js

@@ -1,6 +1,12 @@
 const StyleLintPlugin = require('stylelint-webpack-plugin');
 
 module.exports = {
+  pages: {
+    index: {
+      entry: 'src/main.js',
+      title: 'RepoSense Report',
+    },
+  },
   publicPath: './',
   outputDir: 'build/',
   configureWebpack: {

src/main/java/reposense/report/ReportGenerator.java

@@ -1,7 +1,5 @@
 package reposense.report;
 
-import static org.apache.commons.text.StringEscapeUtils.escapeHtml4;
-
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.PrintWriter;
@@ -65,8 +63,6 @@ public class ReportGenerator {
 
     // zip file which contains all the report template files
     private static final String TEMPLATE_FILE = "/templateZip.zip";
-    private static final String INDEX_PAGE_TEMPLATE = "index.html";
-    private static final String INDEX_PAGE_DEFAULT_TITLE = "<title>reposense</title>";
 
     private static final String MESSAGE_INVALID_CONFIG_JSON = "%s Ignoring the config provided by %s (%s).";
     private static final String MESSAGE_ERROR_CREATING_DIRECTORY =
@@ -82,6 +78,8 @@ public class ReportGenerator {
     private static final String MESSAGE_COMPLETE_ANALYSIS = "Analysis of %s (%s) completed!";
     private static final String MESSAGE_REPORT_GENERATED = "The report is generated at %s";
     private static final String MESSAGE_BRANCH_DOES_NOT_EXIST = "Branch %s does not exist in %s! Analysis terminated.";
+    private static final String MESSAGE_MISSING_TEMPLATE =
+            "Unable to find template file. Proceeding to generate report...";
 
     private static final String LOG_ERROR_CLONING = "Failed to clone from %s";
     private static final String LOG_ERROR_EXPANDING_COMMIT = "Cannot expand %s, it shall remain unexpanded";
@@ -124,7 +122,7 @@ public static List<Path> generateReposReport(List<RepoConfiguration> configs, St
             LocalDateTime untilDate, boolean isSinceDateProvided, boolean isUntilDateProvided, int numCloningThreads,
             int numAnalysisThreads, Supplier<String> reportGenerationTimeProvider, ZoneId zoneId,
             boolean shouldFreshClone) throws IOException {
-        prepareTemplateFile(reportConfig, outputPath);
+        prepareTemplateFile(outputPath);
         if (Files.exists(Paths.get(assetsPath))) {
             FileUtil.copyDirectoryContents(assetsPath, outputPath, assetsFilesWhiteList);
         }
@@ -153,26 +151,15 @@ public static List<Path> generateReposReport(List<RepoConfiguration> configs, St
 
     /**
      * Copies the template file to the specified {@code outputPath} for the repo report to be generated.
-     * @throws IOException if template resource is not found.
+     * @throws IOException if I/O error encountered while copying template file.
      */
-    private static void prepareTemplateFile(ReportConfiguration config, String outputPath) throws IOException {
+    private static void prepareTemplateFile(String outputPath) throws IOException {
         InputStream is = RepoSense.class.getResourceAsStream(TEMPLATE_FILE);
-        FileUtil.copyTemplate(is, outputPath);
-        setReportConfiguration(config, outputPath);
-    }
-
-    private static void setReportConfiguration(ReportConfiguration config, String outputPath) throws IOException {
-        setLandingPageTitle(outputPath, config.getTitle());
-    }
-
-    /**
-     * Set title of template file located at {@code filePath} to {@code pageTitle}
-     */
-    private static void setLandingPageTitle(String filePath, String pageTitle) throws IOException {
-        Path indexPagePath = Paths.get(filePath, INDEX_PAGE_TEMPLATE);
-        String line = new String(Files.readAllBytes(indexPagePath));
-        String newLine = line.replaceAll(INDEX_PAGE_DEFAULT_TITLE, "<title>" + escapeHtml4(pageTitle) + "</title>");
-        Files.write(indexPagePath, newLine.getBytes());
+        if (is != null) {
+            FileUtil.copyTemplate(is, outputPath);
+        } else {
+            logger.warning(MESSAGE_MISSING_TEMPLATE);
+        }
     }
 
     /**