Resilience for failure to detemine task details

In case of failure in resolving one of the following:
- task inputs
- task outputs
- task description

Continue building the task tree. Display the failure reason
instead of the resolved detail in the tree.

Author: dorongold

src/main/groovy/com/dorongold/gradle/tasktree/NodeAction.groovy

@@ -2,6 +2,7 @@ package com.dorongold.gradle.tasktree
 
 import groovy.transform.TupleConstructor
 import org.gradle.api.Action
+import org.gradle.internal.Try
 import org.gradle.internal.graph.GraphRenderer
 import org.gradle.internal.logging.text.StyledTextOutput
 
@@ -47,22 +48,23 @@ class NodeAction implements Action<StyledTextOutput> {
         }
 
         if (withInputs) {
-            printTaskFiles(graphRenderer, taskDetails.fileInputs, "<- ", FailureHeader, Failure)
+            printTaskFiles(graphRenderer, taskDetails.fileInputs, "<- ", 'inputs', FailureHeader, Failure)
         }
         if (withOutputs) {
-            printTaskFiles(graphRenderer, taskDetails.fileOutputs, "-> ", SuccessHeader, Success)
+            printTaskFiles(graphRenderer, taskDetails.fileOutputs, "-> ", 'outputs', SuccessHeader, Success)
         }
     }
 
-    static void printTaskDescription(GraphRenderer graphRenderer, String description, StyledTextOutput.Style textStyle) {
+    static void printTaskDescription(GraphRenderer graphRenderer, Try<String> description, StyledTextOutput.Style textStyle) {
         graphRenderer.output
                 .withStyle(textStyle)
-                .text(" - " + description)
+                .text(" - " + description.getOrMapFailure { e -> "Error! Failure determining description: [${e}]" })
     }
 
-    static void printTaskFiles(GraphRenderer graphRenderer, List<String> files, String prefix, StyledTextOutput.Style prefixStyle, StyledTextOutput.Style textStyle) {
+    static void printTaskFiles(GraphRenderer graphRenderer, Try<List<String>> files, String prefix,
+                               String detailName, StyledTextOutput.Style prefixStyle, StyledTextOutput.Style textStyle) {
         graphRenderer.startChildren()
-        files.eachWithIndex { File file, int i ->
+        files.getOrMapFailure { e -> ["[Error determining ${detailName}: ${e}]"] }.eachWithIndex { String file, int i ->
             graphRenderer.output.println()
             graphRenderer.output
                     .withStyle(Info)

src/main/groovy/com/dorongold/gradle/tasktree/TaskTreeTaskBase.groovy

@@ -1,3 +1,4 @@
+//file:noinspection GrMethodMayBeStatic
 package com.dorongold.gradle.tasktree
 
 import groovy.transform.Canonical
@@ -11,10 +12,15 @@ import org.gradle.api.tasks.diagnostics.internal.TextReportRenderer
 import org.gradle.execution.plan.DefaultExecutionPlan
 import org.gradle.execution.plan.Node
 import org.gradle.initialization.BuildClientMetaData
+import org.gradle.internal.Try
 import org.gradle.internal.graph.GraphRenderer
 import org.gradle.internal.logging.text.StyledTextOutput
+import org.slf4j.Logger
+import org.slf4j.LoggerFactory
 import utils.TaskGraphUtils
 
+import java.util.concurrent.Callable
+
 import static org.gradle.internal.logging.text.StyledTextOutput.Style.FailureHeader
 import static org.gradle.internal.logging.text.StyledTextOutput.Style.Info
 import static org.gradle.internal.logging.text.StyledTextOutput.Style.SuccessHeader
@@ -25,6 +31,9 @@ import static org.gradle.internal.logging.text.StyledTextOutput.Style.UserInput
  * Date: 10/09/15*/
 
 abstract class TaskTreeTaskBase extends AbstractProjectBasedReportTask<TaskReportModel> {
+
+    private static final Logger LOGGER = LoggerFactory.getLogger(TaskTreeTaskBase)
+
     public TextReportRenderer renderer = new TextReportRenderer()
 
     @Internal
@@ -45,6 +54,9 @@ abstract class TaskTreeTaskBase extends AbstractProjectBasedReportTask<TaskRepor
     @Internal
     GraphRenderer graphRenderer
 
+    @Internal
+    Map<Node, TaskDetails> taskDetailsCache = new HashMap<>()
+
     @Override
     protected TextReportRenderer getRenderer() {
         return renderer
@@ -59,9 +71,9 @@ abstract class TaskTreeTaskBase extends AbstractProjectBasedReportTask<TaskRepor
     @EqualsAndHashCode(includes = ['path'])
     static final class TaskDetails {
         String path
-        String description
-        List<String> fileInputs
-        List<String> fileOutputs
+        Try<String> description
+        Try<List<String>> fileInputs
+        Try<List<String>> fileOutputs
 
         Collection<TaskDetails> children
     }
@@ -88,14 +100,22 @@ abstract class TaskTreeTaskBase extends AbstractProjectBasedReportTask<TaskRepor
     }
 
     TaskDetails buildTaskDetails(Node taskNode) {
-        String path = taskNode.task.getIdentityPath() as String
-        String description = taskNode.task.description as String
-        List<String> inputs = taskNode.task.inputs.files as List<String>
-        List<String> outputs = taskNode.task.outputs.files as List<String>
-        return new TaskDetails(path,
-                description,
-                inputs,
-                outputs)
+        taskDetailsCache.computeIfAbsent(taskNode, this::buildTaskDetailsInternal)
+    }
+
+    TaskDetails buildTaskDetailsInternal(Node taskNode) {
+        LOGGER.info("[task-tree plugin]: building task details for task ${taskNode}")
+        String taskPath = taskNode.task.getIdentityPath() as String
+        Try<String> taskDescription = withDescription ? tryBuildDetailForTaskPath(taskPath, 'description',
+                () -> taskNode.task.description as String) : null
+        Try<List<String>> taskInputs = withInputs ? tryBuildDetailForTaskPath(taskPath, 'inputs',
+                () -> taskNode.task.inputs.files.collect { it.toString() }) : null
+        Try<List<String>> taskOutputs = withOutputs ? tryBuildDetailForTaskPath(taskPath, 'outputs',
+                () -> taskNode.task.outputs.files.collect { it.toString() }) : null
+        return new TaskDetails(taskPath,
+                taskDescription,
+                taskInputs,
+                taskOutputs)
     }
 
     @Override
@@ -186,4 +206,13 @@ abstract class TaskTreeTaskBase extends AbstractProjectBasedReportTask<TaskRepor
 
     }
 
+    static <U> Try<U> tryBuildDetailForTaskPath(String taskPath, String detailName, Callable<U> failable) {
+        try {
+            return Try.successful(failable.call())
+        } catch (Exception e) {
+            LOGGER.info("[task-tree plugin]: Error determining ${detailName} for task ${taskPath}", e)
+            return Try.failure(e)
+        }
+    }
+
 }

src/test/groovy/com/dorongold/gradle/tasktree/TaskTreeTaskTest.groovy

@@ -201,6 +201,23 @@ class TaskTreeTaskTest extends Specification {
         result.output.contains expectedOutputProjectPersonService()
     }
 
+    @UsesSample('failures/')
+    def "taskTree with failures determining task inputs"() {
+        when:
+        def result = GradleRunner.create()
+                .withProjectDir(sampleProject.dir)
+                .withArguments('compileGroovy', 'taskTree', '--with-inputs')
+                .withPluginClasspath()
+                .build()
+
+        then:
+        result.output =~ expectedOutputProjectFailures()
+
+        result.task(":taskTree").outcome == SUCCESS
+        result.task(":compileGroovy").outcome == SKIPPED
+
+    }
+
 
     static String expectedOutputAllArgumentsWithoutRepeat(Path projectRoot) {
         """
@@ -605,6 +622,21 @@ Project ':services:personService'
 '''.stripIndent()
     }
 
+    static String expectedOutputProjectFailures() {
+        $/
+------------------------------------------------------------
+Root project 'failures'
+------------------------------------------------------------
+
+:compileGroovy
+     <-  \[Error determining inputs: org.gradle.api.GradleException: Cannot infer Groovy class path because no Groovy Jar was found on class path: \[.*failures/build/classes/java/main\]\]
+\\--- :compileJava
+
+
+\(\*\) - subtree omitted \(printed previously\)
+/$.stripIndent()
+    }
+
     private void populateBuildFile() {
         buildFile << """
             plugins {

src/test/resources/samples/failures/build.gradle

@@ -0,0 +1,6 @@
+plugins {
+    id 'java'
+    id 'groovy' // applying the groovy plugin without setting groovy runtime causes groovyCompile to fail resolving inputs: https://docs.gradle.org/current/userguide/groovy_plugin.html#sec:automatic_configuration_of_groovyclasspath
+    id 'com.dorongold.task-tree'
+}
+

src/test/resources/samples/failures/settings.gradle

@@ -0,0 +1 @@
+rootProject.name = "failures"

src/test/resources/samples/failures/src/main/groovy/org/gradle/sample/Main.groovy

@@ -0,0 +1,7 @@
+package samples.failures.src.main.groovy.org.gradle.sample
+
+class Main {
+    static void main(String[] args) {
+        System.out.println("Hello, world!")
+    }
+}