[JENKINS-76222] Add support for modified files in report filtering (#1259)

See [JENKINS-76222](https://issues.jenkins.io/browse/JENKINS-76222)

Author: akash-manna-sky

src/main/java/edu/hm/hafner/analysis/IssuesInModifiedCodeMarker.java

@@ -31,9 +31,29 @@ public void markIssuesInModifiedCode(final Report report, final Map<String, Set<
         }
     }
 
+    /**
+     * Finds and marks all issues that are in modified files, regardless of whether they affect specific lines.
+     *
+     * @param report
+     *         the report with the issues to scan
+     * @param modifiedFiles
+     *         a set of modified file names
+     */
+    public void markIssuesInModifiedFiles(final Report report, final Set<String> modifiedFiles) {
+        for (String fileName : modifiedFiles) {
+            report.filter(issue -> affectsModifiedFile(issue, fileName))
+                    .stream()
+                    .forEach(Issue::markAsPartOfModifiedCode);
+        }
+    }
+
     private boolean affectsChangedLineInFile(final Issue issue, final String fileName, final Set<Integer> lines) {
+        return affectsModifiedFile(issue, fileName) && lines.stream().anyMatch(issue::affectsLine);
+    }
+
+    private boolean affectsModifiedFile(final Issue issue, final String fileName) {
         var normalizedPath = PATH_UTIL.getRelativePath(fileName);
 
-        return issue.getFileName().endsWith(normalizedPath) && lines.stream().anyMatch(issue::affectsLine);
+        return issue.getFileName().endsWith(normalizedPath);
     }
 }

src/test/java/edu/hm/hafner/analysis/IssuesInModifiedCodeMarkerTest.java

@@ -94,6 +94,93 @@ void shouldMarkIssuesIfFileNameUsesWindowsPath() {
         assertThatIssuesToString(report).containsExactly(TO_STRING_MODIFIED, TO_STRING_MODIFIED);
     }
 
+    @Test
+    void shouldNotMarkAnythingForEmptySetOfFiles() {
+        var report = createReportWithTwoIssues();
+
+        assertThatModifiedCodeMarkers(report).containsExactly(false, false);
+
+        var marker = new IssuesInModifiedCodeMarker();
+        marker.markIssuesInModifiedFiles(report, Set.of());
+        assertThatModifiedCodeMarkers(report).containsExactly(false, false);
+        assertThatIssuesToString(report).containsExactly(TO_STRING_UNMODIFIED, TO_STRING_UNMODIFIED);
+    }
+
+    @Test
+    void shouldNotMarkIfFileDoesNotMatch() {
+        var report = createReportWithTwoIssues();
+
+        var marker = new IssuesInModifiedCodeMarker();
+        marker.markIssuesInModifiedFiles(report, Set.of("/wrong/path/code.txt"));
+
+        assertThatModifiedCodeMarkers(report).containsExactly(false, false);
+        assertThatIssuesToString(report).containsExactly(TO_STRING_UNMODIFIED, TO_STRING_UNMODIFIED);
+    }
+
+    @Test
+    void shouldMarkIssuesIfOneFileMatches() {
+        var report = createReportWithTwoIssues();
+
+        var marker = new IssuesInModifiedCodeMarker();
+        marker.markIssuesInModifiedFiles(report, Set.of("/part/of/modified/code.txt"));
+
+        assertThatModifiedCodeMarkers(report).containsExactly(true, false);
+        assertThatIssuesToString(report).containsExactly(TO_STRING_MODIFIED, TO_STRING_UNMODIFIED);
+    }
+
+    @Test
+    void shouldMarkIssuesIfAllFilesMatch() {
+        var report = createReportWithTwoIssues();
+
+        var marker = new IssuesInModifiedCodeMarker();
+        marker.markIssuesInModifiedFiles(report, Set.of(
+                "/part/of/modified/code.txt",
+                "/part/of/additional/modified/code.txt"));
+
+        assertThatModifiedCodeMarkers(report).containsExactly(true, true);
+        assertThatIssuesToString(report).containsExactly(TO_STRING_MODIFIED, TO_STRING_MODIFIED);
+    }
+
+    @Test
+    void shouldMarkIssuesIfFilesPrefixMatchesForFiles() {
+        var report = createReportWithTwoIssues();
+
+        var marker = new IssuesInModifiedCodeMarker();
+        marker.markIssuesInModifiedFiles(report, Set.of("modified/code.txt", "additional/modified/code.txt"));
+
+        assertThatModifiedCodeMarkers(report).containsExactly(true, true);
+        assertThatIssuesToString(report).containsExactly(TO_STRING_MODIFIED, TO_STRING_MODIFIED);
+    }
+
+    @Test
+    void shouldMarkIssuesIfFileNameUsesWindowsPathForFiles() {
+        var report = createReportWithTwoIssues();
+
+        var marker = new IssuesInModifiedCodeMarker();
+        marker.markIssuesInModifiedFiles(report, Set.of("modified\\code.txt", "additional\\modified\\code.txt"));
+
+        assertThatModifiedCodeMarkers(report).containsExactly(true, true);
+        assertThatIssuesToString(report).containsExactly(TO_STRING_MODIFIED, TO_STRING_MODIFIED);
+    }
+
+    @Test
+    void shouldMarkAllIssuesInFileRegardlessOfLineNumbers() {
+        var report = new Report();
+        try (var builder = new IssueBuilder()) {
+            builder.setFileName("/part/of/modified/code.txt");
+            report.add(builder.setLineStart(1).setLineEnd(5).build());
+            report.add(builder.setLineStart(10).setLineEnd(15).build());
+            report.add(builder.setLineStart(100).setLineEnd(200).build());
+            builder.setFileName("/other/file.txt");
+            report.add(builder.setLineStart(1).setLineEnd(5).build());
+        }
+
+        var marker = new IssuesInModifiedCodeMarker();
+        marker.markIssuesInModifiedFiles(report, Set.of("modified/code.txt"));
+
+        assertThatModifiedCodeMarkers(report).containsExactly(true, true, true, false);
+    }
+
     private AbstractListAssert<?, List<? extends String>, String, ObjectAssert<String>> assertThatIssuesToString(
             final Report report) {
         return assertThat(report.get()).extracting(Issue::toString);