lint: Add a new lint rule to check for use of printStackTrace.

Author: jainkuniya

.github/PULL_REQUEST_TEMPLATE.md

@@ -13,6 +13,4 @@ Please make sure these boxes are checked before submitting your pull request - t
 
 - [ ] If new feature is implemeted then it is compatible with Night theme too.
 
-- [ ] Used `Zlog.logException(e)` instead of `e.printStackTrace()`
-
 - [ ] Commit messages are well-written.

app/build.gradle

@@ -107,6 +107,7 @@ dependencies {
     }
 
     testCompile 'junit:junit:4.12'
+    compile project(':customLintAAR')
 
 }
 

customLintAAR/.gitignore

@@ -0,0 +1 @@
+/build

customLintAAR/build.gradle

@@ -0,0 +1,52 @@
+apply plugin: 'com.android.library'
+apply plugin: 'maven'
+
+
+android {
+    compileSdkVersion 24
+    buildToolsVersion "23.0.2"
+
+    defaultConfig {
+        minSdkVersion 13
+        targetSdkVersion 23
+        versionCode 1
+        versionName "1.0"
+    }
+    buildTypes {
+        release {
+            minifyEnabled false
+        }
+    }
+}
+
+dependencies {
+    compile fileTree(dir: 'libs', include: ['*.jar'])
+    testCompile 'junit:junit:4.12'
+}
+
+
+/*
+ * rules for including "lint.jar" in aar
+ */
+configurations {
+    lintJarImport
+}
+
+dependencies {
+    lintJarImport project(path: ':customlintjar', configuration: "lintJarOutput")
+}
+
+task copyLintJar(type: Copy) {
+    from (configurations.lintJarImport) {
+        rename {
+            String fileName ->
+                'lint.jar'
+        }
+    }
+    into 'build/intermediates/lint/'
+}
+
+project.afterEvaluate {
+    def compileLintTask = project.tasks.find { it.name == 'compileLint' }
+    compileLintTask.dependsOn(copyLintJar)
+}

customLintAAR/src/main/AndroidManifest.xml

@@ -0,0 +1,6 @@
+<manifest xmlns:android="http://schemas.android.com/apk/res/android"
+    package="com.zulip.android.customlintarr">
+
+    <application  android:label="@string/app_name"/>
+
+</manifest>

customLintAAR/src/main/res/values/strings.xml

@@ -0,0 +1,3 @@
+<resources>
+    <string name="app_name">Custom Lint</string>
+</resources>

customlintjar/.gitignore

@@ -0,0 +1 @@
+/build

customlintjar/build.gradle

@@ -0,0 +1,25 @@
+apply plugin: 'java'
+
+dependencies {
+    compile fileTree(include: ['*.jar'], dir: 'libs')
+    compile 'com.android.tools.lint:lint:25.0.0'
+    compile 'com.android.tools.lint:lint-api:25.0.0'
+    compile 'com.android.tools.lint:lint-checks:25.0.0'
+    testCompile 'com.android.tools.lint:lint-tests:24.5.0'
+}
+
+jar {
+    manifest {
+        attributes('Lint-Registry': 'com.zulip.android.customlintrules.MyIssueRegistry')
+    }
+}
+
+configurations {
+    lintJarOutput
+}
+
+dependencies {
+    lintJarOutput files(jar)
+}
+
+defaultTasks 'assemble'

customlintjar/src/main/java/com/zulip/android/customlintrules/MyIssueRegistry.java

@@ -0,0 +1,20 @@
+package com.zulip.android.customlintrules;
+
+import com.android.tools.lint.client.api.IssueRegistry;
+import com.android.tools.lint.detector.api.Issue;
+import com.zulip.android.customlintrules.detectors.PrintStackTraceDetector;
+
+import java.util.Arrays;
+import java.util.List;
+
+@SuppressWarnings("unused")
+public class MyIssueRegistry extends IssueRegistry {
+    @Override
+    public List<Issue> getIssues() {
+        System.out.println("********Working on custom lint check!!!********");
+        return Arrays.asList(
+                PrintStackTraceDetector.ISSUE);
+
+    }
+}
+

customlintjar/src/main/java/com/zulip/android/customlintrules/detectors/PrintStackTraceDetector.java

@@ -0,0 +1,77 @@
+package com.zulip.android.customlintrules.detectors;
+
+import com.android.annotations.NonNull;
+import com.android.tools.lint.detector.api.Category;
+import com.android.tools.lint.detector.api.ClassContext;
+import com.android.tools.lint.detector.api.Detector;
+import com.android.tools.lint.detector.api.Implementation;
+import com.android.tools.lint.detector.api.Issue;
+import com.android.tools.lint.detector.api.Scope;
+import com.android.tools.lint.detector.api.Severity;
+
+import org.objectweb.asm.tree.ClassNode;
+import org.objectweb.asm.tree.MethodInsnNode;
+import org.objectweb.asm.tree.MethodNode;
+
+import java.util.Collections;
+import java.util.EnumSet;
+import java.util.List;
+
+/**
+ * Custom lint rule to check e.printStackTrace() is used or not
+ */
+public class PrintStackTraceDetector extends Detector
+        implements Detector.ClassScanner {
+
+    private static final Class<? extends Detector> DETECTOR_CLASS = PrintStackTraceDetector.class;
+    private static final EnumSet<Scope> DETECTOR_SCOPE = Scope.CLASS_FILE_SCOPE;
+
+    private static final Implementation IMPLEMENTATION = new Implementation(
+            DETECTOR_CLASS,
+            DETECTOR_SCOPE
+    );
+
+    private static final String ISSUE_ID = "ZLog";
+    private static final String ISSUE_DESCRIPTION = "Use `ZLog.logException(e);` instead of `e.printStackTrace();` ";
+    private static final String ISSUE_EXPLANATION = "`ZLog.logException(e);` print stacktrace as well as report that to the Crashlytics. " +
+            "It provides real-time crash reporting, down to the exact line of code that caused the crash and we can start work as soon as it is reported. "+
+            "All logged exceptions are appeared as 'non-fatal' issue in the Fabric dashboard. It helps in knowing when app gone to unexpected state like" +
+            " malformed network data, misunderstanding of requirements, a logic error etc. Whenever exception is caught it prevent app to crash and continue the app flow(as well as report to Dashboard)";
+    private static final Category ISSUE_CATEGORY = Category.USABILITY;
+    private static final int ISSUE_PRIORITY = 9;
+    private static final Severity ISSUE_SEVERITY = Severity.ERROR;
+
+    public static final Issue ISSUE = Issue.create(
+            ISSUE_ID,
+            ISSUE_DESCRIPTION,
+            ISSUE_EXPLANATION,
+            ISSUE_CATEGORY,
+            ISSUE_PRIORITY,
+            ISSUE_SEVERITY,
+            IMPLEMENTATION
+    );
+    private static final String FUNCTION_NAME = "printStackTrace";
+
+    @Override
+    public List<String> getApplicableCallNames() {
+        return Collections.singletonList(FUNCTION_NAME);
+    }
+
+    @Override
+    public List<String> getApplicableMethodNames() {
+        return Collections.singletonList(FUNCTION_NAME);
+    }
+
+    @Override
+    public void checkCall(@NonNull ClassContext context,
+                          @NonNull ClassNode classNode,
+                          @NonNull MethodNode method,
+                          @NonNull MethodInsnNode call) {
+        context.report(ISSUE,
+                method,
+                call,
+                context.getLocation(call),
+                "You must use our `ZLog.logException(e);` ");
+
+    }
+}