Fix part of #5343: Building proto with coverage results for data proc…

…essing (#5439)

<!-- READ ME FIRST: Please fill in the explanation section below and
check off every point from the Essential Checklist! -->
## Explanation
<!--
- Explain what your PR does. If this PR fixes an existing bug, please
include
- "Fixes #bugnum:" in the explanation so that GitHub can auto-close the
issue
  - when this PR is merged.
  -->
Fixes part of #5343 

### Project
[PR 1.4 of Project 4.1]

### Changes Made
- Introduced `coverage.proto` to store the coverage data generated
during coverage analysis.
- Parsed coverage data according to the LCOV (geninfo) file format
specifications: [LCOV geninfo
specifications](https://manpages.debian.org/stretch/lcov/geninfo.1.en.html#FILES)
- This maps the Bazel test target to the corresponding SF: source file
path and filters the data to generate the Coverage Report proto that
will only the coverage of the tests related to the single source file.
- With the previous implementation in PR 1.3 to get the related
LocalTest and Test file mappings, we utilize that to run coverage for
both the test and return them as a list of Coverage Report protos.

**To Note:**
- Only the app module has the multi test file case.
- But as of date, the many app module coverage executions fail.
- So to test acquiring multi test coverage execution as list of Coverage
Report Proto, I hardcoded and tested the implementation [[hardcoded
comment](https://github.com/oppia/oppia-android/pull/5439/files#diff-62c81482e7c4b720da2d4efc73a48d10369eee097e0bf3439def6648ff150c23R89-R93)]
(just for testing the actual code wouldn't have that)

**Result:**
A representation of the list of Coverage Report proto is presented
below:

This is the output on running 2 hardcoded test cases:
`math:MathModelTest` and `math:FloatExtensionsTest`
<details>
<summary>List of Coverage Report</summary>
<br>

<pre>
Parsed Coverage Data File:
/home/rddev/.../bazel-out/.../util/parser/math/MathModelTest/coverage.dat
Parsed Coverage Data File:
/home/rddev/.../bazel-out/.../util/math/FloatExtensionsTest/coverage.dat
Coverage Data List: [bazel_test_target:
"//utility/src/test/java/org/oppia/android/util/parser/math:MathModelTest"
covered_file {
file_path:
"utility/src/main/java/org/oppia/android/util/parser/math/MathModel.kt"
  file_sha1_hash: "37eb0c6a3a16c300da100e245e7d320c61cc008f"
  covered_line {
    line_number: 14
    coverage: FULL
  }
  covered_line {
    line_number: 15
    coverage: FULL
  }
  covered_line {
    line_number: 16
    coverage: FULL
  }
  covered_line {
    line_number: 17
    coverage: FULL
  }
  covered_line {
    line_number: 21
    coverage: FULL
  }
  covered_line {
    line_number: 33
    coverage: FULL
  }
  covered_line {
    line_number: 34
    coverage: FULL
  }
  covered_line {
    line_number: 35
    coverage: FULL
  }
  covered_line {
    line_number: 36
    coverage: FULL
  }
  covered_line {
    line_number: 41
    coverage: FULL
  }
  covered_line {
    line_number: 42
    coverage: FULL
  }
  covered_line {
    line_number: 43
    coverage: FULL
  }
  covered_line {
    line_number: 44
    coverage: FULL
  }
  covered_line {
    line_number: 45
    coverage: FULL
  }
  covered_line {
    line_number: 46
    coverage: FULL
  }
  covered_line {
    line_number: 47
    coverage: FULL
  }
  covered_line {
    line_number: 49
    coverage: FULL
  }
  covered_line {
    line_number: 58
    coverage: FULL
  }
  covered_line {
    line_number: 59
    coverage: FULL
  }
  lines_found: 19
  lines_hit: 19
  function_coverage {
    line_number: 58
function_name:
"org/oppia/android/util/parser/math/MathModel$MathModelSignature$Companion::createSignature$utility_src_main_java_org_oppia_android_util_parser_math_math_latex_model_kt
(Ljava/lang/String;FZ)Lorg/oppia/android/util/parser/math/MathModel$MathModelSignature;"
    execution_count: 1
    coverage: FULL
  }
  function_coverage {
    line_number: 33
function_name:
"org/oppia/android/util/parser/math/MathModel$MathModelSignature::<init>
(Ljava/lang/String;IZ)V"
    execution_count: 1
    coverage: FULL
  }
  function_coverage {
    line_number: 35
function_name:
"org/oppia/android/util/parser/math/MathModel$MathModelSignature::getLineHeightHundredX
()I"
    execution_count: 1
    coverage: FULL
  }
  function_coverage {
    line_number: 34
function_name:
"org/oppia/android/util/parser/math/MathModel$MathModelSignature::getRawLatex
()Ljava/lang/String;"
    execution_count: 0
    coverage: NONE
  }
  function_coverage {
    line_number: 36
function_name:
"org/oppia/android/util/parser/math/MathModel$MathModelSignature::getUseInlineRendering
()Z"
    execution_count: 1
    coverage: FULL
  }
  function_coverage {
    line_number: 41
function_name:
"org/oppia/android/util/parser/math/MathModel$MathModelSignature::updateDiskCacheKey
(Ljava/security/MessageDigest;)V"
    execution_count: 1
    coverage: FULL
  }
  function_coverage {
    line_number: 14
function_name: "org/oppia/android/util/parser/math/MathModel::<init>
(Ljava/lang/String;FZ)V"
    execution_count: 1
    coverage: FULL
  }
  function_coverage {
    line_number: 16
function_name:
"org/oppia/android/util/parser/math/MathModel::getLineHeight ()F"
    execution_count: 0
    coverage: NONE
  }
  function_coverage {
    line_number: 15
function_name:
"org/oppia/android/util/parser/math/MathModel::getRawLatex
()Ljava/lang/String;"
    execution_count: 0
    coverage: NONE
  }
  function_coverage {
    line_number: 17
function_name:
"org/oppia/android/util/parser/math/MathModel::getUseInlineRendering
()Z"
    execution_count: 0
    coverage: NONE
  }
  function_coverage {
    line_number: 21
function_name:
"org/oppia/android/util/parser/math/MathModel::toKeySignature
()Lorg/oppia/android/util/parser/math/MathModel$MathModelSignature;"
    execution_count: 1
    coverage: FULL
  }
  functions_found: 11
  functions_hit: 7
  branch_coverage {
    line_number: 46
    block_number: 0
    branch_number: 0
    hit_count: 1
    coverage: FULL
  }
  branch_coverage {
    line_number: 46
    block_number: 0
    branch_number: 1
    hit_count: 1
    coverage: FULL
  }
  branches_found: 2
  branches_hit: 2
}
, bazel_test_target:
"//utility/src/test/java/org/oppia/android/util/math:FloatExtensionsTest"
covered_file {
file_path:
"utility/src/main/java/org/oppia/android/util/math/FloatExtensions.kt"
  file_sha1_hash: "178a2d84e9182a11b41adf34abc0a92a7d365f50"
  covered_line {
    line_number: 28
    coverage: FULL
  }
  covered_line {
    line_number: 36
    coverage: FULL
  }
  covered_line {
    line_number: 43
    coverage: FULL
  }
  lines_found: 3
  lines_hit: 3
  function_coverage {
    line_number: 36
function_name:
"org/oppia/android/util/math/FloatExtensionsKt::isApproximatelyEqualTo
(DD)Z"
    execution_count: 1
    coverage: FULL
  }
  function_coverage {
    line_number: 28
function_name:
"org/oppia/android/util/math/FloatExtensionsKt::isApproximatelyEqualTo
(FF)Z"
    execution_count: 1
    coverage: FULL
  }
  function_coverage {
    line_number: 43
function_name:
"org/oppia/android/util/math/FloatExtensionsKt::toPlainString
(D)Ljava/lang/String;"
    execution_count: 1
    coverage: FULL
  }
  functions_found: 3
  functions_hit: 3
  branch_coverage {
    line_number: 28
    block_number: 0
    branch_number: 0
    hit_count: 1
    coverage: FULL
  }
  branch_coverage {
    line_number: 28
    block_number: 0
    branch_number: 1
    hit_count: 1
    coverage: FULL
  }
  branch_coverage {
    line_number: 36
    block_number: 0
    branch_number: 0
    hit_count: 1
    coverage: FULL
  }
  branch_coverage {
    line_number: 36
    block_number: 0
    branch_number: 1
    hit_count: 1
    coverage: FULL
  }
  branches_found: 4
  branches_hit: 4
}
]
</pre>
</details>

**Representation in Protobuf**
- Function Coverage: Interpreted execution counts to determine coverage
status. Any execution count greater than 0 signifies full coverage,
otherwise considered null.

- Branch Coverage: Determined coverage based on the recorded hit count
for each branch. A hit count greater than 0 denotes full coverage,
otherwise marked as null.

**Usage:**
The stored proto will be used to generate coverage reports in **md** and
**HTML** formats [to be handled in PR 1.5]

## Essential Checklist
<!-- Please tick the relevant boxes by putting an "x" in them. -->
- [x] The PR title and explanation each start with "Fix #bugnum: " (If
this PR fixes part of an issue, prefix the title with "Fix part of
#bugnum: ...".)
- [x] Any changes to
[scripts/assets](https://github.com/oppia/oppia-android/tree/develop/scripts/assets)
files have their rationale included in the PR explanation.
- [x] The PR follows the [style
guide](https://github.com/oppia/oppia-android/wiki/Coding-style-guide).
- [x] The PR does not contain any unnecessary code changes from Android
Studio
([reference](https://github.com/oppia/oppia-android/wiki/Guidance-on-submitting-a-PR#undo-unnecessary-changes)).
- [x] The PR is made from a branch that's **not** called "develop" and
is up-to-date with "develop".
- [ ] The PR is **assigned** to the appropriate reviewers
([reference](https://github.com/oppia/oppia-android/wiki/Guidance-on-submitting-a-PR#clarification-regarding-assignees-and-reviewers-section)).

## For UI-specific PRs only
<!-- Delete these section if this PR does not include UI-related
changes. -->
If your PR includes UI-related changes, then:
- Add screenshots for portrait/landscape for both a tablet & phone of
the before & after UI changes
- For the screenshots above, include both English and pseudo-localized
(RTL) screenshots (see [RTL
guide](https://github.com/oppia/oppia-android/wiki/RTL-Guidelines))
- Add a video showing the full UX flow with a screen reader enabled (see
[accessibility
guide](https://github.com/oppia/oppia-android/wiki/Accessibility-A11y-Guide))
- For PRs introducing new UI elements or color changes, both light and
dark mode screenshots must be included
- Add a screenshot demonstrating that you ran affected Espresso tests
locally & that they're passing

---------

Co-authored-by: Ben Henning <ben@oppia.org>
Co-authored-by: Adhiambo Peres <59600948+adhiamboperes@users.noreply.github.com>

scripts/src/java/org/oppia/android/scripts/coverage/BUILD.bazel

@@ -27,5 +27,6 @@ kt_jvm_library(
     visibility = ["//scripts:oppia_script_binary_visibility"],
     deps = [
         "//scripts/src/java/org/oppia/android/scripts/common:bazel_client",
+        "//scripts/src/java/org/oppia/android/scripts/proto:coverage_java_proto",
     ],
 )

scripts/src/java/org/oppia/android/scripts/coverage/CoverageRunner.kt

@@ -6,7 +6,13 @@ import kotlinx.coroutines.async
 import org.oppia.android.scripts.common.BazelClient
 import org.oppia.android.scripts.common.CommandExecutor
 import org.oppia.android.scripts.common.ScriptBackgroundCoroutineDispatcher
+import org.oppia.android.scripts.proto.Coverage
+import org.oppia.android.scripts.proto.CoverageReport
+import org.oppia.android.scripts.proto.CoveredLine
 import java.io.File
+import java.nio.file.Files
+import java.nio.file.Paths
+import java.security.MessageDigest
 
 /**
  * Class responsible for running coverage analysis asynchronously.
@@ -30,9 +36,12 @@ class CoverageRunner(
    */
   fun runWithCoverageAsync(
     bazelTestTarget: String
-  ): Deferred<List<String>?> {
+  ): Deferred<CoverageReport> {
     return CoroutineScope(scriptBgDispatcher).async {
-      retrieveCoverageResult(bazelTestTarget)
+      val coverageResult = retrieveCoverageResult(bazelTestTarget)
+        ?: error("Failed to retrieve coverage result for $bazelTestTarget")
+
+      coverageDataFileLines(coverageResult, bazelTestTarget)
     }
   }
 
@@ -41,4 +50,67 @@ class CoverageRunner(
   ): List<String>? {
     return bazelClient.runCoverageForTestTarget(bazelTestTarget)
   }
+
+  private fun coverageDataFileLines(
+    coverageData: List<String>,
+    bazelTestTarget: String
+  ): CoverageReport {
+    val extractedFileName = "${extractTargetName(bazelTestTarget)}.kt"
+
+    val sfStartIdx = coverageData.indexOfFirst {
+      it.startsWith("SF:") && it.substringAfter("SF:").substringAfterLast("/") == extractedFileName
+    }
+    if (sfStartIdx == -1) throw IllegalArgumentException("File not found")
+    val eofIdx = coverageData.subList(sfStartIdx, coverageData.size).indexOfFirst {
+      it.startsWith("end_of_record")
+    }
+    if (eofIdx == -1) throw IllegalArgumentException("End of record not found")
+
+    val fileSpecificCovDatLines = coverageData.subList(sfStartIdx, sfStartIdx + eofIdx + 1)
+
+    val coverageDataProps = fileSpecificCovDatLines.groupBy { line ->
+      line.substringBefore(":")
+    }.mapValues { (_, lines) ->
+      lines.map { line ->
+        line.substringAfter(":").split(",")
+      }
+    }
+
+    val filePath = coverageDataProps["SF"]?.firstOrNull()?.get(0)
+      ?: throw IllegalArgumentException("File path not found")
+
+    val linesFound = coverageDataProps["LF"]?.singleOrNull()?.single()?.toInt() ?: 0
+    val linesHit = coverageDataProps["LH"]?.singleOrNull()?.single()?.toInt() ?: 0
+
+    val coveredLines = coverageDataProps["DA"]?.map { (lineNumStr, hitCountStr) ->
+      CoveredLine.newBuilder().apply {
+        this.lineNumber = lineNumStr.toInt()
+        this.coverage = if (hitCountStr.toInt() > 0) Coverage.FULL else Coverage.NONE
+      }.build()
+    }.orEmpty()
+
+    val file = File(repoRoot, filePath)
+    val fileSha1Hash = calculateSha1(file.absolutePath)
+
+    return CoverageReport.newBuilder()
+      .setBazelTestTarget(bazelTestTarget)
+      .setFilePath(filePath)
+      .setFileSha1Hash(fileSha1Hash)
+      .addAllCoveredLine(coveredLines)
+      .setLinesFound(linesFound)
+      .setLinesHit(linesHit)
+      .build()
+  }
+}
+
+private fun extractTargetName(bazelTestTarget: String): String {
+  val targetName = bazelTestTarget.substringAfterLast(":").trim()
+  return targetName.removeSuffix("LocalTest").removeSuffix("Test")
+}
+
+private fun calculateSha1(filePath: String): String {
+  val fileBytes = Files.readAllBytes(Paths.get(filePath))
+  val digest = MessageDigest.getInstance("SHA-1")
+  val hashBytes = digest.digest(fileBytes)
+  return hashBytes.joinToString("") { "%02x".format(it) }
 }

scripts/src/java/org/oppia/android/scripts/coverage/RunCoverage.kt

@@ -5,6 +5,7 @@ import org.oppia.android.scripts.common.BazelClient
 import org.oppia.android.scripts.common.CommandExecutor
 import org.oppia.android.scripts.common.CommandExecutorImpl
 import org.oppia.android.scripts.common.ScriptBackgroundCoroutineDispatcher
+import org.oppia.android.scripts.proto.CoverageReport
 import org.oppia.android.scripts.proto.TestFileExemptions
 import java.io.File
 import java.util.concurrent.TimeUnit
@@ -78,7 +79,7 @@ class RunCoverage(
    * @return a list of lists containing coverage data for each requested test target, if
    *     the file is exempted from having a test file, an empty list is returned
    */
-  fun execute(): List<List<String>> {
+  fun execute(): List<CoverageReport> {
     val testFileExemptionList = loadTestFileExemptionsProto(testFileExemptionTextProto)
       .testFileExemptionList
       .filter { it.testFileNotRequired }
@@ -97,15 +98,11 @@ class RunCoverage(
     val testTargets = bazelClient.retrieveBazelTargets(testFilePaths)
 
     return testTargets.mapNotNull { testTarget ->
-      val coverageData = runCoverageForTarget(testTarget)
-      if (coverageData == null) {
-        println("Coverage data for $testTarget is null")
-      }
-      coverageData
+      runCoverageForTarget(testTarget)
     }
   }
 
-  private fun runCoverageForTarget(testTarget: String): List<String>? {
+  private fun runCoverageForTarget(testTarget: String): CoverageReport {
     return runBlocking {
       CoverageRunner(rootDirectory, scriptBgDispatcher, commandExecutor)
         .runWithCoverageAsync(testTarget.removeSuffix(".kt"))

scripts/src/java/org/oppia/android/scripts/proto/BUILD.bazel

@@ -21,6 +21,17 @@ java_proto_library(
     deps = [":affected_tests_proto"],
 )
 
+oppia_proto_library(
+    name = "coverage_proto",
+    srcs = ["coverage.proto"],
+)
+
+java_proto_library(
+    name = "coverage_java_proto",
+    visibility = ["//scripts:oppia_script_library_visibility"],
+    deps = [":coverage_proto"],
+)
+
 oppia_proto_library(
     name = "filename_pattern_validation_checks_proto",
     srcs = ["filename_pattern_validation_checks.proto"],

scripts/src/java/org/oppia/android/scripts/proto/coverage.proto

@@ -0,0 +1,40 @@
+syntax = "proto3";
+
+package proto;
+
+option java_package = "org.oppia.android.scripts.proto";
+option java_multiple_files = true;
+
+// Coverage Report that contains the bazel coverage data retrieved from the
+// Bazel coverage execution.
+message CoverageReport {
+  // The test target for which the coverage report is generated.
+  string bazel_test_target = 1;
+  // The relative path of the covered file.
+  string file_path = 2;
+  // SHA-1 hash of the file content at the time of report (to guard against changes).
+  string file_sha1_hash = 3;
+  // The lines of code covered in the report.
+  repeated CoveredLine covered_line = 4;
+  // The total number of lines found in the covered file.
+  int32 lines_found = 5;
+  // The total number of lines hit in the covered file.
+  int32 lines_hit = 6;
+}
+
+// Information about a single line that was covered during the tests.
+message CoveredLine {
+  // The line number of the covered line.
+  int32 line_number = 1;
+  // The coverage status of the covered line.
+  Coverage coverage = 2;
+}
+
+enum Coverage {
+  // Coverage status is unspecified.
+  UNSPECIFIED = 0;
+  // The line, branch, or function is fully covered, ie. executed atleast once.
+  FULL = 1;
+  // The line, branch, or function is not covered at all.
+  NONE = 2;
+}

scripts/src/java/org/oppia/android/scripts/testing/TestBazelWorkspace.kt

@@ -62,6 +62,7 @@ class TestBazelWorkspace(private val temporaryRootFolder: TemporaryFolder) {
    */
   fun addSourceAndTestFileWithContent(
     filename: String,
+    testFilename: String,
     sourceContent: String,
     testContent: String,
     sourceSubpackage: String,
@@ -73,10 +74,9 @@ class TestBazelWorkspace(private val temporaryRootFolder: TemporaryFolder) {
       sourceSubpackage
     )
 
-    val testFileName = "${filename}Test"
     addTestContentAndBuildFile(
       filename,
-      testFileName,
+      testFilename,
       testContent,
       sourceSubpackage,
       testSubpackage

scripts/src/javatests/org/oppia/android/scripts/common/BazelClientTest.kt

@@ -422,6 +422,7 @@ class BazelClientTest {
 
     testBazelWorkspace.addSourceAndTestFileWithContent(
       filename = "TwoSum",
+      testFilename = "TwoSumTest",
       sourceContent = sourceContent,
       testContent = testContent,
       sourceSubpackage = "coverage/main/java/com/example",

scripts/src/javatests/org/oppia/android/scripts/coverage/CoverageRunnerTest.kt

@@ -9,6 +9,9 @@ import org.junit.Test
 import org.junit.rules.TemporaryFolder
 import org.oppia.android.scripts.common.CommandExecutorImpl
 import org.oppia.android.scripts.common.ScriptBackgroundCoroutineDispatcher
+import org.oppia.android.scripts.proto.Coverage
+import org.oppia.android.scripts.proto.CoverageReport
+import org.oppia.android.scripts.proto.CoveredLine
 import org.oppia.android.scripts.testing.TestBazelWorkspace
 import org.oppia.android.testing.assertThrows
 import java.util.concurrent.TimeUnit
@@ -103,6 +106,7 @@ class CoverageRunnerTest {
 
     testBazelWorkspace.addSourceAndTestFileWithContent(
       filename = "TwoSum",
+      testFilename = "TwoSumTest",
       sourceContent = sourceContent,
       testContent = testContent,
       sourceSubpackage = "coverage/main/java/com/example",
@@ -114,28 +118,38 @@ class CoverageRunnerTest {
         "//coverage/test/java/com/example:TwoSumTest"
       ).await()
     }
-    val expectedResult = listOf(
-      "SF:coverage/main/java/com/example/TwoSum.kt",
-      "FN:7,com/example/TwoSum${'$'}Companion::sumNumbers (II)Ljava/lang/Object;",
-      "FN:3,com/example/TwoSum::<init> ()V",
-      "FNDA:1,com/example/TwoSum${'$'}Companion::sumNumbers (II)Ljava/lang/Object;",
-      "FNDA:0,com/example/TwoSum::<init> ()V",
-      "FNF:2",
-      "FNH:1",
-      "BRDA:7,0,0,1",
-      "BRDA:7,0,1,1",
-      "BRDA:7,0,2,1",
-      "BRDA:7,0,3,1",
-      "BRF:4",
-      "BRH:4",
-      "DA:3,0",
-      "DA:7,1",
-      "DA:8,1",
-      "DA:10,1",
-      "LH:3",
-      "LF:4",
-      "end_of_record"
-    )
+
+    val expectedResult = CoverageReport.newBuilder()
+      .setBazelTestTarget("//coverage/test/java/com/example:TwoSumTest")
+      .setFilePath("coverage/main/java/com/example/TwoSum.kt")
+      .setFileSha1Hash("f6fb075e115775f6729615a79f0e7e34fe9735b5")
+      .addCoveredLine(
+        CoveredLine.newBuilder()
+          .setLineNumber(3)
+          .setCoverage(Coverage.NONE)
+          .build()
+      )
+      .addCoveredLine(
+        CoveredLine.newBuilder()
+          .setLineNumber(7)
+          .setCoverage(Coverage.FULL)
+          .build()
+      )
+      .addCoveredLine(
+        CoveredLine.newBuilder()
+          .setLineNumber(8)
+          .setCoverage(Coverage.FULL)
+          .build()
+      )
+      .addCoveredLine(
+        CoveredLine.newBuilder()
+          .setLineNumber(10)
+          .setCoverage(Coverage.FULL)
+          .build()
+      )
+      .setLinesFound(4)
+      .setLinesHit(3)
+      .build()
 
     assertThat(result).isEqualTo(expectedResult)
   }