Add coverage calculation and badge

.codecov.yml

@@ -0,0 +1,22 @@
+codecov:
+  notify:
+    require_ci_to_pass: yes
+  strict_yaml_branch: main  # only use the latest copy on the main branch
+
+ignore:
+  - "model/v1/model.pb.go"
+  - "proto-gen/*/*"
+
+coverage:
+  precision: 2
+  round: down
+  range: "95...100"
+  status:
+    project:
+      default:
+        enabled: yes
+        target: 95%
+    patch:
+      default:
+        enabled: yes
+        target: 95%

.github/actions/upload-codecov/action.yml

@@ -0,0 +1,34 @@
+# Copyright (c) 2023 The Jaeger Authors.
+# SPDX-License-Identifier: Apache-2.0
+
+# Codecov upload often fails on rate limits if used without a token.
+# See https://github.com/codecov/codecov-action/issues/837
+# This action embeds a token directly.
+# We cannot define it as "secret" as we need it accessible from forks.
+
+name: 'Upload coverage to codecov'
+description: 'Uploads coverage to codecov with retries'
+inputs:
+  files:
+    description: 'Coverage files to upload'
+    required: true
+  flags:
+    description: 'Flags for codecov'
+    required: true
+runs:
+  using: 'composite'
+  steps:
+    - name: Retry upload
+      uses: Wandalen/[email protected]
+      with:
+        attempt_limit: 6
+        # sleep 10 seconds between retries
+        attempt_delay: 10000
+        action: codecov/codecov-action@v5
+        with: |
+          slug: jaegertracing/jaeger-idl
+          files: ${{ inputs.files }}
+          flags: ${{ inputs.flags }}
+          verbose: true
+          fail_ci_if_error: true
+          token: 95fab3d9-8038-40ba-ac56-0d8bd91390a4

.github/workflows/ci-unit-tests.yml

@@ -35,13 +35,11 @@ jobs:
     - name: Run unit tests
       run: make test-ci
 
-    - name: Upload coverage reports to Codecov
-      uses: codecov/codecov-action@v5
+    - name: upload code coverage
+      uses: ./.github/actions/upload-codecov
       with:
-        slug: jaegertracing/jaeger-idl
-        verbose: true
-        fail_ci_if_error: true
-        token: 95fab3d9-8038-40ba-ac56-0d8bd91390a4
+        files: coverage.txt
+        flags: unittests
 
   test-code-gen:
     runs-on: ubuntu-latest

.gitignore

@@ -1,3 +1,4 @@
 .idea/
 gen-*/
 .proto-gen-polyglot/
+coverage.txt

Makefile

@@ -40,6 +40,7 @@ swagger-validate:
 clean:
 	rm -rf *gen-* || true
 	rm -rf .*gen-* || true
+	rm -rf coverage.txt
 
 .PHONY: thrift
 thrift:	thrift-image clean $(THRIFT_FILES)

README.md

@@ -1,4 +1,5 @@
 # jaeger-idl [![Build Status][ci-img]][ci]
+[![Coverage Status][cov-img]][cov]
 
 A set of shared Thrift and Protobuf data model definitions used by the Jaeger components.
 
@@ -35,3 +36,5 @@ See [CONTRIBUTING](./CONTRIBUTING.md).
 
 [ci-img]: https://github.com/jaegertracing/jaeger-idl/actions/workflows/ci-unit-tests.yml/badge.svg
 [ci]: https://github.com/jaegertracing/jaeger-idl/actions/workflows/ci-unit-tests.yml
+[cov-img]: https://codecov.io/gh/jaegertracing/jaeger-idl/branch/main/graph/badge.svg
+[cov]: https://codecov.io/gh/jaegertracing/jaeger-idl/branch/main/