Emit root-relative paths in JSON coverage output

Per-file coverage keys, group file lists, and minimum_coverage_by_file
error keys now use `project_filename` (root-relative) instead of
`filename` (absolute). Consumers already have `meta.root` if they
need to reconstruct an absolute path.

The frontend's `shortenFilename` simplifies to stripping the leading
`/` — no more root parameter threaded through the render pipeline.

Author: sferik

features/step_definitions/json_steps.rb

@@ -4,13 +4,12 @@
   cd(".") do
     json_report = JSON.parse(File.read("coverage/coverage.json"))
     coverage_hash = json_report.fetch "coverage"
-    directory = Dir.pwd
 
-    faked_project = coverage_hash.fetch("#{directory}/lib/faked_project.rb")
+    faked_project = coverage_hash.fetch("/lib/faked_project.rb")
     expect(faked_project["lines"]).to eq [nil, nil, 1, 1, 1, nil, nil, nil, 5, 3, nil, nil, 1]
     expect(faked_project["lines_covered_percent"]).to be_a(Float)
 
-    some_class = coverage_hash.fetch("#{directory}/lib/faked_project/some_class.rb")
+    some_class = coverage_hash.fetch("/lib/faked_project/some_class.rb")
     expect(some_class["lines"]).to eq [nil, nil, 1, 1, 1, nil, 1, 2, nil, nil, 1, 1, nil, nil, 1, 1, 1, nil, 0, nil, nil, 0, nil, nil, 1, nil, 1, 0, nil, nil]
     expect(some_class["lines_covered_percent"]).to be_a(Float)
   end

html_frontend/src/app.ts

@@ -272,8 +272,9 @@ function fmtPct(pct: number): string {
   return (Math.floor(pct * 100) / 100).toFixed(2);
 }
 
-function shortenFilename(filename: string, root: string): string {
-  return filename.replace(root, '.').replace(/^\.\//, '');
+function shortenFilename(filename: string): string {
+  // Paths in the JSON output are already root-relative with a leading `/`.
+  return filename.replace(/^\//, '');
 }
 
 function fileId(filename: string): string {
@@ -413,9 +414,9 @@ function buildMissedMethodLines(methods: MethodEntry[] | undefined): Set<number>
   return set;
 }
 
-function renderSourceFile(filename: string, data: FileCoverage, root: string, branchCoverage: boolean, methodCoverage: boolean): string {
+function renderSourceFile(filename: string, data: FileCoverage, branchCoverage: boolean, methodCoverage: boolean): string {
   const id = fileId(filename);
-  const shortName = shortenFilename(filename, root);
+  const shortName = shortenFilename(filename);
   const coveredLines = data.covered_lines;
   const missedLines = data.missed_lines;
   const totalLines = coveredLines + missedLines;
@@ -481,7 +482,6 @@ function renderFileList(
   title: string,
   filenames: string[],
   allCoverage: Record<string, FileCoverage>,
-  root: string,
   branchCoverage: boolean,
   methodCoverage: boolean
 ): string {
@@ -534,7 +534,7 @@ function renderFileList(
   for (const fn of filenames) {
     const f = allCoverage[fn];
     if (!f) continue;
-    const shortName = shortenFilename(fn, root);
+    const shortName = shortenFilename(fn);
     const id = fileId(fn);
     const coveredLines = f.covered_lines;
     const relevantLines = coveredLines + f.missed_lines;
@@ -569,7 +569,6 @@ function renderPage(data: CoverageData): void {
   const meta = data.meta;
   const branchCoverage = meta.branch_coverage;
   const methodCoverage = meta.method_coverage;
-  const root = meta.root;
 
   // Page title and favicon
   document.title = `Code coverage for ${meta.project_name}`;
@@ -585,11 +584,11 @@ function renderPage(data: CoverageData): void {
 
   // Content: file lists
   const content = document.getElementById('content')!;
-  content.innerHTML = renderFileList('All Files', allFiles, data.coverage, root, branchCoverage, methodCoverage);
+  content.innerHTML = renderFileList('All Files', allFiles, data.coverage, branchCoverage, methodCoverage);
 
   for (const groupName of Object.keys(data.groups)) {
     const groupFiles = data.groups[groupName].files || [];
-    content.innerHTML += renderFileList(groupName, groupFiles, data.coverage, root, branchCoverage, methodCoverage);
+    content.innerHTML += renderFileList(groupName, groupFiles, data.coverage, branchCoverage, methodCoverage);
   }
 
   // Build id → filename lookup map for O(1) source file materialization
@@ -599,7 +598,6 @@ function renderPage(data: CoverageData): void {
   }
   (window as any)._simplecovIdMap = idToFilename;
   (window as any)._simplecovFiles = data.coverage;
-  (window as any)._simplecovRoot = root;
   (window as any)._simplecovBranchCoverage = branchCoverage;
   (window as any)._simplecovMethodCoverage = methodCoverage;
 
@@ -849,14 +847,13 @@ function materializeSourceFile(sourceFileId: string): HTMLElement | null {
 
   const idMap = (window as any)._simplecovIdMap as Record<string, string>;
   const coverage = (window as any)._simplecovFiles as Record<string, FileCoverage>;
-  const root = (window as any)._simplecovRoot as string;
   const branchCov = (window as any)._simplecovBranchCoverage as boolean;
   const methodCov = (window as any)._simplecovMethodCoverage as boolean;
 
   const targetFilename = idMap[sourceFileId];
   if (!targetFilename) return null;
 
-  const html = renderSourceFile(targetFilename, coverage[targetFilename], root, branchCov, methodCov);
+  const html = renderSourceFile(targetFilename, coverage[targetFilename], branchCov, methodCov);
   const container = document.querySelector('.source_files')!;
   const wrapper = document.createElement('div');
   wrapper.innerHTML = html;

lib/simplecov/formatter/json_formatter/result_hash_formatter.rb

@@ -27,15 +27,15 @@ def format_total
 
         def format_files
           @result.files.each do |source_file|
-            formatted_result[:coverage][source_file.filename] =
+            formatted_result[:coverage][source_file.project_filename] =
               format_source_file(source_file)
           end
         end
 
         def format_groups
           @result.groups.each do |name, file_list|
             group_data = format_coverage_statistics(file_list.coverage_statistics)
-            group_data[:files] = file_list.map(&:filename)
+            group_data[:files] = file_list.map(&:project_filename)
             formatted_result[:groups][name] = group_data
           end
         end
@@ -63,7 +63,7 @@ def format_minimum_coverage_by_file_errors
             key = CRITERION_KEYS.fetch(violation.fetch(:criterion))
             bucket = formatted_result[:errors][:minimum_coverage_by_file] ||= {}
             criterion_errors = bucket[key] ||= {}
-            criterion_errors[violation.fetch(:filename)] = {expected: violation.fetch(:expected), actual: violation.fetch(:actual)}
+            criterion_errors[violation.fetch(:project_filename)] = {expected: violation.fetch(:expected), actual: violation.fetch(:actual)}
           end
         end
 

spec/fixtures/json/sample.json

@@ -19,7 +19,7 @@
     }
   },
   "coverage": {
-    "/STUB_WORKING_DIRECTORY/spec/fixtures/json/sample.rb": {
+    "/spec/fixtures/json/sample.rb": {
       "lines": [
         null,
         1,

spec/fixtures/json/sample_groups.json

@@ -19,7 +19,7 @@
     }
   },
   "coverage": {
-    "/STUB_WORKING_DIRECTORY/spec/fixtures/json/sample.rb": {
+    "/spec/fixtures/json/sample.rb": {
       "lines": [
         null,
         1,
@@ -90,7 +90,7 @@
         "strength": 0.0
       },
       "files": [
-        "/STUB_WORKING_DIRECTORY/spec/fixtures/json/sample.rb"
+        "/spec/fixtures/json/sample.rb"
       ]
     }
   },

spec/fixtures/json/sample_with_branch.json

@@ -26,7 +26,7 @@
     }
   },
   "coverage": {
-    "/STUB_WORKING_DIRECTORY/spec/fixtures/json/sample.rb": {
+    "/spec/fixtures/json/sample.rb": {
       "lines": [
         null,
         1,

spec/fixtures/json/sample_with_method.json

@@ -26,7 +26,7 @@
     }
   },
   "coverage": {
-    "/STUB_WORKING_DIRECTORY/spec/fixtures/json/sample.rb": {
+    "/spec/fixtures/json/sample.rb": {
       "lines": [
         null,
         1,

spec/json_formatter_spec.rb

@@ -34,7 +34,7 @@
           "percent" => 66.66666666666667,
           "strength" => 0.6666666666666666
         )
-        expect(json_output.fetch("coverage").fetch(source_fixture("json/sample.rb"))).to include(
+        expect(json_output.fetch("coverage").fetch(project_fixture_filename("json/sample.rb"))).to include(
           "lines_covered_percent" => 66.66666666666667
         )
       end
@@ -150,7 +150,7 @@
         errors = json_output.fetch("errors")
         expect(errors).to eq(
           "minimum_coverage_by_file" => {
-            "lines" => {source_fixture("json/sample.rb") => {"expected" => 95, "actual" => 90.0}}
+            "lines" => {project_fixture_filename("json/sample.rb") => {"expected" => 95, "actual" => 90.0}}
           }
         )
       end
@@ -182,7 +182,7 @@
         errors = json_output.fetch("errors")
         expect(errors).to eq(
           "minimum_coverage_by_file" => {
-            "branches" => {source_fixture("json/sample.rb") => {"expected" => 75, "actual" => 50.0}}
+            "branches" => {project_fixture_filename("json/sample.rb") => {"expected" => 75, "actual" => 50.0}}
           }
         )
       end
@@ -289,10 +289,11 @@
         res.created_at = fixed_time
 
         # right now SimpleCov works mostly on global state, hence setting the groups that way
-        # would be global state --> Mocking is better here
+        # would be global state --> Mocking is better here. `map` ignores the block
+        # and returns the stubbed value — so stub it to the project-relative path directly.
         mock_file_list = double("File List",
                                 coverage_statistics: {line: line_stats},
-                                map: [sample_filename])
+                                map: [project_fixture_filename("json/sample.rb")])
         allow(res).to receive_messages(
           groups: {"My Group" => mock_file_list}
         )
@@ -324,6 +325,10 @@ def json_result(filename)
     JSON.parse(file)
   end
 
+  def project_fixture_filename(path)
+    source_fixture(path).delete_prefix(SimpleCov.root)
+  end
+
   STUB_WORKING_DIRECTORY = "STUB_WORKING_DIRECTORY"
   STUB_COMMAND_NAME = "STUB_COMMAND_NAME"
   STUB_PROJECT_NAME = "STUB_PROJECT_NAME"