Address review feedback

1. Output detailed hash data as json
2. Use a different serialization format for targethashes to avoid
   ambiguity

cli/src/main/kotlin/com/bazel_diff/cli/GenerateHashesCommand.kt

@@ -137,8 +137,8 @@ class GenerateHashesCommand : Callable<Int> {
     var ignoredRuleHashingAttributes: Set<String> = emptySet()
 
     @CommandLine.Option(
-        names = ["-d", "--depsFile"],
-        description = ["Path to the file where dependency edges are written to. If not specified, the dependency edges will not be written to a file."],
+        names = ["-d", "--depEdgesFile"],
+        description = ["Path to the file where dependency edges are written to. If not specified, the dependency edges will not be written to a file. Needed for computing build graph distance metrics. See bazel-diff docs for more details about build graph distance metrics."],
         scope = CommandLine.ScopeType.INHERIT,
         defaultValue = CommandLine.Parameters.NULL_VALUE
     )

cli/src/main/kotlin/com/bazel_diff/cli/GetImpactedTargetsCommand.kt

@@ -40,7 +40,7 @@ class GetImpactedTargetsCommand : Callable<Int> {
     lateinit var finalHashesJSONPath: File
 
     @CommandLine.Option(
-        names = ["-d", "--depsFile"],
+        names = ["-d", "--depEdgesFile"],
         description = ["Path to the file where dependency edges are. If specified, build graph distance metrics will be computed from the given hash data."],
         scope = CommandLine.ScopeType.INHERIT,
         defaultValue = CommandLine.Parameters.NULL_VALUE
@@ -58,7 +58,7 @@ class GetImpactedTargetsCommand : Callable<Int> {
     @CommandLine.Option(
         names = ["-o", "--output"],
         scope = CommandLine.ScopeType.LOCAL,
-        description = ["Filepath to write the impacted Bazel targets to, newline separated. If not specified, the targets will be written to STDOUT."],
+        description = ["Filepath to write the impacted Bazel targets to. If using depEdgesFile: formatted in json, otherwise: newline separated. If not specified, the output will be written to STDOUT."],
     )
     var outputPath: File? = null
 
@@ -78,30 +78,17 @@ class GetImpactedTargetsCommand : Callable<Int> {
         val from = deserialiser.executeTargetHash(startingHashesJSONPath)
         val to = deserialiser.executeTargetHash(finalHashesJSONPath)
 
-        val typeFilter = TargetTypeFilter(targetType, to)
-
-        val impactedTargetsStream = if (depsMappingJSONPath != null) {
-            val depsMapping = deserialiser.deserializeDeps(depsMappingJSONPath!!)
-            CalculateImpactedTargetsInteractor().executeWithDistances(from, to, depsMapping)
-            .filterKeys { typeFilter.accepts(it) }
-            .map { (label, metrics) ->
-                "${label}~${metrics.targetDistance}~${metrics.packageDistance}"
-            }.stream()
-        } else {
-            CalculateImpactedTargetsInteractor().execute(from, to)
-            .filter { typeFilter.accepts(it) }
-            .stream()
-        }
-
-        return try {
-            BufferedWriter(when (val path = outputPath) {
+        val outputWriter = BufferedWriter(when (val path = outputPath) {
                 null -> FileWriter(FileDescriptor.out)
                 else -> FileWriter(path)
-            }).use { writer ->
-                impactedTargetsStream.forEach { line ->
-                    writer.write(line)
-                    writer.write("\n")
-                }
+        })
+
+        return try {
+            if (depsMappingJSONPath != null) {
+                val depsMapping = deserialiser.deserializeDeps(depsMappingJSONPath!!)
+                CalculateImpactedTargetsInteractor().executeWithDistances(from, to, depsMapping, outputWriter, targetType)
+            } else {
+                CalculateImpactedTargetsInteractor().execute(from, to, outputWriter, targetType)
             }
             CommandLine.ExitCode.OK
         } catch (e: IOException) {
@@ -122,5 +109,11 @@ class GetImpactedTargetsCommand : Callable<Int> {
                 "Incorrect final hashes: file doesn't exist or can't be read."
             )
         }
+        if (depsFile != null && !depsFile.canRead()) {
+            throw CommandLine.ParameterException(
+                spec.commandLine(),
+                "Incorrect dep edges file: file doesn't exist or can't be read."
+            )
+        }
     }
 }

cli/src/main/kotlin/com/bazel_diff/hash/TargetDigest.kt

@@ -8,11 +8,11 @@ data class TargetDigest(
     val deps: List<String>? = null,
 ) {
     fun clone(newDeps: List<String>? = null): TargetDigest {
-        var newDeps = newDeps
+        var toUse = newDeps
         if (newDeps == null) {
-            newDeps = deps
+            toUse = deps
         }
-        return TargetDigest(overallDigest.clone(), directDigest.clone(), newDeps)
+        return TargetDigest(overallDigest.clone(), directDigest.clone(), toUse)
     }
 }
 

cli/src/main/kotlin/com/bazel_diff/hash/TargetHash.kt

@@ -7,11 +7,11 @@ data class TargetHash(
     val deps: List<String>? = null
 ) {
     val hashWithType by lazy {
-        "${type}#${hash}#${directHash}"
+        "${type}#${hash}~${directHash}"
     }
 
     val totalHash by lazy {
-        "${hash}#${directHash}"
+        "${hash}~${directHash}"
     }
 
     fun toJson(includeTargetType: Boolean): String {
@@ -30,9 +30,15 @@ data class TargetHash(
         fun fromJson(json: String): TargetHash {
             val parts = json.split("#")
             return when (parts.size) {
-                2 -> TargetHash("", parts[0], parts[1])
-                3 -> TargetHash(parts[0], parts[1], parts[2])
-                else -> throw IllegalArgumentException("Invalid JSON format")
+                1 -> Pair("", parts[0])
+                2 -> Pair(parts[0], parts[1])
+                else -> throw IllegalArgumentException("Invalid targetHash format: $json")
+            }.let { (type, hash) ->
+                val hashes = hash.split("~")
+                when (hashes.size) {
+                    2 -> TargetHash(type, hashes[0], hashes[1])
+                    else -> throw IllegalArgumentException("Invalid targetHash format: $json")
+                }
             }
         }
     }

cli/src/main/kotlin/com/bazel_diff/interactor/CalculateImpactedTargetsInteractor.kt

@@ -2,8 +2,11 @@ package com.bazel_diff.interactor
 
 import com.bazel_diff.hash.TargetHash
 import com.google.common.collect.Maps
+import com.google.gson.Gson
 import org.koin.core.component.KoinComponent
+import org.koin.core.component.inject
 import java.io.File
+import java.io.Writer
 import java.util.concurrent.ConcurrentMap
 import java.util.concurrent.ConcurrentHashMap
 import java.util.stream.Stream
@@ -16,6 +19,7 @@ data class TargetDistanceMetrics(
 ) {}
 
 class CalculateImpactedTargetsInteractor : KoinComponent {
+    private val gson: Gson by inject()
 
     @VisibleForTesting
     class InvalidDependencyEdgesException(message: String) : Exception(message)
@@ -25,10 +29,24 @@ class CalculateImpactedTargetsInteractor : KoinComponent {
     INDIRECT
     }
 
-    fun execute(from: Map<String, TargetHash>, to: Map<String, TargetHash>): Set<String> {
+    fun execute(from: Map<String, TargetHash>, to: Map<String, TargetHash>, outputWriter: Writer, targetTypes: Set<String>?) {
         /**
          * This call might be faster if end hashes is a sorted map
          */
+        val typeFilter = TargetTypeFilter(targetTypes, to)
+
+        computeSimpleImpactedTargets(from, to)
+        .filter { typeFilter.accepts(it) }
+        .let { impactedTargets ->
+            outputWriter.use { writer ->
+                impactedTargets.forEach {
+                    writer.write("$it\n")
+                }
+            }
+        }
+    }
+
+    fun computeSimpleImpactedTargets(from: Map<String, TargetHash>, to: Map<String, TargetHash>): Set<String> {
         val difference = Maps.difference(to, from)
         val onlyInEnd: Set<String> = difference.entriesOnlyOnLeft().keys
         val changed: Set<String> = difference.entriesDiffering().keys
@@ -39,7 +57,27 @@ class CalculateImpactedTargetsInteractor : KoinComponent {
         return impactedTargets
     }
 
-    fun executeWithDistances(from: Map<String, TargetHash>, to: Map<String, TargetHash>, depEdges: Map<String, List<String>>): Map<String, TargetDistanceMetrics> {
+    fun executeWithDistances(from: Map<String, TargetHash>, to: Map<String, TargetHash>, depEdges: Map<String, List<String>>, outputWriter: Writer, targetTypes: Set<String>?) {
+        val typeFilter = TargetTypeFilter(targetTypes, to)
+
+        computeAllDistances(from, to, depEdges)
+        .filterKeys { typeFilter.accepts(it) }
+        .let { impactedTargets ->
+            outputWriter.use { writer ->
+                writer.write(gson.toJson(
+                    impactedTargets.map{
+                        mapOf(
+                            "label" to it.key,
+                            "targetDistance" to it.value.targetDistance,
+                            "packageDistance" to it.value.packageDistance
+                        )
+                    }
+                ))
+            }
+        }
+    }
+
+    fun computeAllDistances(from: Map<String, TargetHash>, to: Map<String, TargetHash>, depEdges: Map<String, List<String>>): Map<String, TargetDistanceMetrics> {
         val difference = Maps.difference(to, from)
 
         val newLabels = difference.entriesOnlyOnLeft().keys

cli/src/test/kotlin/com/bazel_diff/e2e/E2ETest.kt

@@ -3,6 +3,8 @@ package com.bazel_diff.e2e
 import assertk.assertThat
 import assertk.assertions.isEqualTo
 import com.bazel_diff.cli.BazelDiff
+import com.google.gson.Gson
+import com.google.gson.reflect.TypeToken
 import org.junit.Ignore
 import org.junit.Rule
 import org.junit.Test
@@ -46,11 +48,23 @@ class E2ETest {
                 listOf("get-impacted-targets", "-sh", from.absolutePath, "-fh", to.absolutePath, "-o", impactedTargetsOutput.absolutePath) + extraGetImpactedTargetsArgs + if (computeDistances) listOf("-d", depsFile.absolutePath) else emptyList()
         )
 
-        val actual: Set<String> = impactedTargetsOutput.readLines().filter { it.isNotBlank() }.toSet()
-        val expected: Set<String> =
-                javaClass.getResourceAsStream(expectedResultFile).use { it.bufferedReader().readLines().filter { it.isNotBlank() }.toSet() }
+        if (!computeDistances) {
+                val actual: Set<String> = impactedTargetsOutput.readLines().filter { it.isNotBlank() }.toSet()
+                val expected: Set<String> =
+                        javaClass.getResourceAsStream(expectedResultFile).use { it.bufferedReader().readLines().filter { it.isNotBlank() }.toSet() }
+
+                assertThat(actual).isEqualTo(expected)
+        } else {
+                // When computing target distances, the output format is json. Read the files and assert the sorted contents.
+                val gson = Gson()
+                val shape = object : TypeToken<List<Map<String, Any>>>() {}.type
+                val actual = gson.fromJson<List<Map<String, Any>>>(impactedTargetsOutput.readText(), shape).sortedBy { it["label"] as String }
+                val expected = javaClass.getResourceAsStream(expectedResultFile).use {
+                        gson.fromJson<List<Map<String, Any>>>(it.bufferedReader().readText(), shape).sortedBy { it["label"] as String }
+                }
 
-        assertThat(actual).isEqualTo(expected)
+                assertThat(actual).isEqualTo(expected)
+        }
     }
 
     @Test

cli/src/test/kotlin/com/bazel_diff/interactor/CalculateImpactedTargetsInteractorTest.kt

@@ -34,7 +34,7 @@ class CalculateImpactedTargetsInteractorTest : KoinTest {
         end["3"] = "d"
         val endHashes = end.mapValues { TargetHash("", it.value, it.value) }
 
-        val impacted = interactor.execute(startHashes, endHashes)
+        val impacted = interactor.computeSimpleImpactedTargets(startHashes, endHashes)
         assertThat(impacted).containsExactlyInAnyOrder(
             "1", "3"
         )
@@ -53,7 +53,7 @@ class CalculateImpactedTargetsInteractorTest : KoinTest {
         makeIndirectlyChanged(endHashes, "//:3")
 
         val interactor = CalculateImpactedTargetsInteractor()
-        val impacted = interactor.executeWithDistances(startHashes, endHashes, depEdges)
+        val impacted = interactor.computeAllDistances(startHashes, endHashes, depEdges)
 
         assertThat(impacted).containsOnly(
             "//:1" to TargetDistanceMetrics(0, 0),
@@ -72,7 +72,7 @@ class CalculateImpactedTargetsInteractorTest : KoinTest {
         )
 
         val interactor = CalculateImpactedTargetsInteractor()
-        val impacted = interactor.executeWithDistances(startHashes, endHashes, mapOf())
+        val impacted = interactor.computeAllDistances(startHashes, endHashes, mapOf())
 
         assertThat(impacted).containsOnly(
             "//:1" to TargetDistanceMetrics(0, 0),
@@ -91,7 +91,7 @@ class CalculateImpactedTargetsInteractorTest : KoinTest {
         makeIndirectlyChanged(endHashes, "//:2", "//:3")
 
         val interactor = CalculateImpactedTargetsInteractor()
-        val impacted = interactor.executeWithDistances(startHashes, endHashes, depEdges)
+        val impacted = interactor.computeAllDistances(startHashes, endHashes, depEdges)
 
         assertThat(impacted).containsOnly(
             "//:1" to TargetDistanceMetrics(0,0),
@@ -111,7 +111,7 @@ class CalculateImpactedTargetsInteractorTest : KoinTest {
         makeIndirectlyChanged(endHashes, "//A:2", "//B:3", "//B:4", "//C:5")
 
         val interactor = CalculateImpactedTargetsInteractor()
-        val impacted = interactor.executeWithDistances(startHashes, endHashes, depEdges)
+        val impacted = interactor.computeAllDistances(startHashes, endHashes, depEdges)
 
         assertThat(impacted).containsOnly(
             "//A:1" to TargetDistanceMetrics(0,0),
@@ -139,7 +139,7 @@ class CalculateImpactedTargetsInteractorTest : KoinTest {
         makeIndirectlyChanged(endHashes, "//A:target_1", "//A:target_2", "//A:target_3", "//A:target_4", "//B:target", "//C:target", "//D:target", "//final:final")
 
         val interactor = CalculateImpactedTargetsInteractor()
-        val impacted = interactor.executeWithDistances(startHashes, endHashes, depEdges)
+        val impacted = interactor.computeAllDistances(startHashes, endHashes, depEdges)
 
         assertThat(impacted["//final:final"]).isEqualTo(TargetDistanceMetrics(4,2))
     }
@@ -161,7 +161,7 @@ class CalculateImpactedTargetsInteractorTest : KoinTest {
         makeIndirectlyChanged(endHashes, "//:2", "//:3")
 
         val interactor = CalculateImpactedTargetsInteractor()
-        val impacted = interactor.executeWithDistances(startHashes, endHashes, depEdges)
+        val impacted = interactor.computeAllDistances(startHashes, endHashes, depEdges)
 
         assertThat(impacted).containsOnly(
             "//:1" to TargetDistanceMetrics(0,0),
@@ -181,12 +181,12 @@ class CalculateImpactedTargetsInteractorTest : KoinTest {
 
         val interactor = CalculateImpactedTargetsInteractor()
         assertThat {
-            interactor.executeWithDistances(startHashes, endHashes, depEdges)
+            interactor.computeAllDistances(startHashes, endHashes, depEdges)
         }.isFailure().message().isEqualTo("//:2 was indirectly impacted, but has no impacted dependencies.")
 
         assertThat {
             // empty dep edges
-            interactor.executeWithDistances(startHashes, endHashes, mapOf())
+            interactor.computeAllDistances(startHashes, endHashes, mapOf())
         }.isFailure().message().isEqualTo("//:2 was indirectly impacted, but has no dependencies.")
 
     }

cli/src/test/kotlin/com/bazel_diff/interactor/DeserialiseHashesInteractorTest.kt

@@ -31,7 +31,7 @@ class DeserialiseHashesInteractorTest : KoinTest {
     @Test
     fun testDeserialisation() {
         val file = temp.newFile().apply {
-            writeText("""{"target-name":"hash#direct"}""")
+            writeText("""{"target-name":"hash~direct"}""")
         }
 
         val actual = interactor.executeTargetHash(file)
@@ -44,9 +44,9 @@ class DeserialiseHashesInteractorTest : KoinTest {
     fun testDeserialisationWithType() {
         val file = temp.newFile().apply {
             writeText("""{
-                |  "target-1":"GeneratedFile#hash1#direct1", 
-                |  "target-2":"Rule#hash2#direct2",
-                |  "target-3":"SourceFile#hash3#direct3"
+                |  "target-1":"GeneratedFile#hash1~direct1", 
+                |  "target-2":"Rule#hash2~direct2",
+                |  "target-3":"SourceFile#hash3~direct3"
                 |}""".trimMargin())
         }
 

cli/src/test/resources/fixture/impacted_targets_distances-1-2-rule-sourcefile.txt

@@ -1,3 +1,5 @@
-//test/java/com/integration:bazel-diff-integration-test-lib~0~0
-//test/java/com/integration:bazel-diff-integration-tests~1~0
-//test/java/com/integration:TestStringGenerator.java~0~0
+[
+{"label": "//test/java/com/integration:bazel-diff-integration-test-lib", "targetDistance": 0, "packageDistance": 0},
+{"label": "//test/java/com/integration:bazel-diff-integration-tests", "targetDistance": 1, "packageDistance": 0},
+{"label": "//test/java/com/integration:TestStringGenerator.java", "targetDistance": 0, "packageDistance": 0}
+]

cli/src/test/resources/fixture/impacted_targets_distances-1-2.txt

@@ -1,8 +1,10 @@
-//test/java/com/integration:libbazel-diff-integration-test-lib-src.jar~0~0
-//test/java/com/integration:TestStringGenerator.java~0~0
-//test/java/com/integration:bazel-diff-integration-test-lib~0~0
-//test/java/com/integration:bazel-diff-integration-tests-src.jar~2~0
-//test/java/com/integration:libbazel-diff-integration-test-lib.jar~0~0
-//test/java/com/integration:bazel-diff-integration-tests~1~0
-//test/java/com/integration:bazel-diff-integration-tests_deploy-src.jar~2~0
-//test/java/com/integration:bazel-diff-integration-tests.jar~2~0
+[
+{"label": "//test/java/com/integration:libbazel-diff-integration-test-lib-src.jar", "targetDistance": 0, "packageDistance": 0},
+{"label": "//test/java/com/integration:TestStringGenerator.java", "targetDistance": 0, "packageDistance": 0},
+{"label": "//test/java/com/integration:bazel-diff-integration-test-lib", "targetDistance": 0, "packageDistance": 0},
+{"label": "//test/java/com/integration:bazel-diff-integration-tests-src.jar", "targetDistance": 2, "packageDistance": 0},
+{"label": "//test/java/com/integration:libbazel-diff-integration-test-lib.jar", "targetDistance": 0, "packageDistance": 0},
+{"label": "//test/java/com/integration:bazel-diff-integration-tests", "targetDistance": 1, "packageDistance": 0},
+{"label": "//test/java/com/integration:bazel-diff-integration-tests_deploy-src.jar", "targetDistance": 2, "packageDistance": 0},
+{"label": "//test/java/com/integration:bazel-diff-integration-tests.jar", "targetDistance": 2, "packageDistance": 0}
+]