tests(unit): add coverage for spec/01-unit (#10754)

* tests(unit): add coverage workflow

run tests with luacov once a week
aggregate the results and print it

* tests(unit): parametrize build path + dispatchable

make build path parametric
enable dispatchable workflow in build & coverage

.ci/luacov-stats-aggregator.lua

@@ -0,0 +1,69 @@
+-- Aggregates stats from multiple luacov stat files.
+-- If different stats files contain coverage information of common
+-- source files, it assumes the provided stats refer to the same
+-- version of the source files.
+
+-- Example stats for a 12 lines file `my/file.lua`
+-- that received hits on lines 3, 4, 9:
+-- 
+-- ["my/file.lua"] = {
+--   [3] = 1,
+--   [4] = 3,
+--   [9] = 2,
+--   max = 12,
+--   max_hits = 3
+-- }
+--
+
+local luacov_stats = require "luacov.stats"
+local luacov_reporter = require "luacov.reporter"
+
+local all_stats = {}
+
+
+-- load parameters
+local params = {...}
+local base_path = params[1] or "./luacov-stats-out-"
+local file_name = params[2] or "luacov.stats.out"
+local output = params[3] or file_name
+
+
+-- load stats - appends incremental index to base_path to load all the artifacts
+local loaded_stats = {}
+local index = 0
+repeat
+  index = index + 1
+  local stats_file = base_path .. index .. "/" .. file_name
+  local loaded = luacov_stats.load(stats_file)
+  if loaded then
+    loaded_stats[#loaded_stats + 1] = loaded
+    print("loading file: " .. stats_file)
+  end
+until not loaded
+
+
+-- aggregate stats by file name
+for _, stat_data in ipairs(loaded_stats) do
+  for f_name, f_data in pairs(stat_data) do
+    if all_stats[f_name] then
+      assert(
+        all_stats[f_name].max == f_data.max,
+        "number of lines in file " .. f_name .. " is inconsistent"
+      )
+      -- combine stats (add line hits)
+      for i = 1, all_stats[f_name].max do
+        if all_stats[f_name][i] or f_data[i] then
+          all_stats[f_name][i] = (all_stats[f_name][i] or 0) + (f_data[i] or 0)
+        end
+      end
+      all_stats[f_name].max_hits = math.max(all_stats[f_name].max_hits, f_data.max_hits)
+
+    else
+      all_stats[f_name] = f_data
+    end
+  end
+end
+luacov_stats.save(output, all_stats)
+
+-- generate report
+luacov_reporter.report()

.github/workflows/build.yml

@@ -0,0 +1,55 @@
+name: Build
+on:
+  workflow_call:
+    inputs:
+      build-root-suffix:
+        required: true
+        type: string
+
+env:
+  BUILD_ROOT: ${{ github.workspace }}${{ inputs.build-root-suffix }}
+
+jobs:
+  build:
+    name: Build dependencies
+    runs-on: ubuntu-22.04
+
+    steps:
+    - name: Checkout Kong source code
+      uses: actions/checkout@v3
+
+    - name: Lookup build cache
+      id: cache-deps
+      uses: actions/cache@v3
+      with:
+        path: |
+          ${{ env.BUILD_ROOT }}
+        key: ${{ hashFiles('.requirements', 'kong-*.rockspec', '.bazelversion', '.bazelrc', 'build/**', 'BUILD.bazel', 'WORKSPACE', '.github/workflows/build_and_test.yml') }}
+
+    - name: Install packages
+      if: steps.cache-deps.outputs.cache-hit != 'true'
+      run: sudo apt update && sudo apt install libyaml-dev valgrind libprotobuf-dev
+
+    - name: Build Kong
+      if: steps.cache-deps.outputs.cache-hit != 'true'
+      run: |
+        make build-kong
+        BUILD_PREFIX=$BUILD_ROOT/kong-dev
+        export PATH="$BUILD_PREFIX/bin:$BUILD_PREFIX/openresty/nginx/sbin:$BUILD_PREFIX/openresty/bin:$PATH"
+        chmod +rw -R $BUILD_PREFIX
+        nginx -V
+        ldd $(which nginx)
+        luarocks
+
+    - name: Bazel Outputs
+      uses: actions/upload-artifact@v3
+      if: failure()
+      with:
+        name: bazel-outputs
+        path: |
+          bazel-out/_tmp/actions
+
+    - name: Build Dev Kong dependencies
+      if: steps.cache-deps.outputs.cache-hit != 'true'
+      run: |
+        make install-dev-rocks

.github/workflows/build_and_coverage.yml

@@ -0,0 +1,84 @@
+name: Build & Test Coverage
+on:
+  schedule:
+    - cron: "15 0 * * 0"
+  workflow_dispatch:
+
+env:
+  BUILD_ROOT: ${{ github.workspace }}/bazel-bin/build
+
+jobs:
+  build:
+    uses: ./.github/workflows/build.yml
+    with:
+      build-root-suffix: /bazel-bin/build
+
+  unit-tests:
+    name: Unit tests
+    runs-on: ubuntu-22.04
+    needs: build
+
+    services:
+      postgres:
+        image: postgres:13
+        env:
+          POSTGRES_USER: kong
+          POSTGRES_DB: kong
+          POSTGRES_HOST_AUTH_METHOD: trust
+        ports:
+          - 5432:5432
+        options: --health-cmd pg_isready --health-interval 5s --health-timeout 5s --health-retries 8
+
+    steps:
+    - name: Checkout Kong source code
+      uses: actions/checkout@v3
+
+    - name: Lookup build cache
+      id: cache-deps
+      uses: actions/cache@v3
+      with:
+        path: |
+          ${{ env.BUILD_ROOT }}
+        key: ${{ hashFiles('.requirements', 'kong-*.rockspec', '.bazelversion', '.bazelrc', 'build/**', 'BUILD.bazel', 'WORKSPACE', '.github/workflows/build_and_test.yml') }}
+
+    - name: Unit tests
+      env:
+        KONG_TEST_PG_DATABASE: kong
+        KONG_TEST_PG_USER: kong
+      run: |
+          source ${{ env.BUILD_ROOT }}/kong-dev-venv.sh
+          bin/busted spec/01-unit --coverage
+    
+    - name: Archive coverage stats file
+      uses: actions/upload-artifact@v3
+      if: success()
+      with:
+        name: luacov-stats-out-1
+        retention-days: 1
+        path: |
+          luacov.stats.out
+    
+# TODO: run jobs with the remaining tests (with coverage enabled) and archive each artifact as luacov-stats-out-{i}
+
+  aggregator:
+    needs: [unit-tests] # add dependencies for all the test jobs
+    name: Luacov stats aggregator
+    runs-on: ubuntu-22.04
+
+    steps:
+    - name: Checkout source code
+      uses: actions/checkout@v3
+
+    - name: Install requirements
+      run: |
+        sudo apt-get update && sudo apt-get install -y luarocks
+        sudo luarocks install luacov
+
+    # Download all archived coverage stats files
+    - uses: actions/download-artifact@v3
+
+    - name: Stats aggregation
+      shell: bash
+      run: |
+        lua .ci/luacov-stats-aggregator.lua "luacov-stats-out-" "luacov.stats.out"
+        awk '/Summary/,0' luacov.report.out

.github/workflows/build_and_test.yml

@@ -26,48 +26,9 @@ env:
 
 jobs:
   build:
-    name: Build dependencies
-    runs-on: ubuntu-22.04
-
-    steps:
-    - name: Checkout Kong source code
-      uses: actions/checkout@v3
-
-    - name: Lookup build cache
-      id: cache-deps
-      uses: actions/cache@v3
-      with:
-        path: |
-          ${{ env.BUILD_ROOT }}
-        key: ${{ hashFiles('.requirements', 'kong-*.rockspec', '.bazelversion', '.bazelrc', 'build/**', 'BUILD.bazel', 'WORKSPACE', '.github/workflows/build_and_test.yml') }}
-
-    - name: Install packages
-      if: steps.cache-deps.outputs.cache-hit != 'true'
-      run: sudo apt update && sudo apt install libyaml-dev valgrind libprotobuf-dev
-
-    - name: Build Kong
-      if: steps.cache-deps.outputs.cache-hit != 'true'
-      run: |
-        make build-kong
-        BUILD_PREFIX=$BUILD_ROOT/kong-dev
-        export PATH="$BUILD_PREFIX/bin:$BUILD_PREFIX/openresty/nginx/sbin:$BUILD_PREFIX/openresty/bin:$PATH"
-        chmod +rw -R $BUILD_PREFIX
-        nginx -V
-        ldd $(which nginx)
-        luarocks
-
-    - name: Bazel Outputs
-      uses: actions/upload-artifact@v3
-      if: failure()
-      with:
-        name: bazel-outputs
-        path: |
-          bazel-out/_tmp/actions
-
-    - name: Build Dev Kong dependencies
-      if: steps.cache-deps.outputs.cache-hit != 'true'
-      run: |
-        make install-dev-rocks
+    uses: ./.github/workflows/build.yml
+    with:
+      build-root-suffix: /bazel-bin/build
 
   lint-doc-and-unit-tests:
     name: Lint, Doc and Unit tests

.luacov

@@ -0,0 +1,15 @@
+return {
+
+  runreport = true,
+
+  include = {
+    "kong$",
+    "kong%/.+$",
+  },
+
+  exclude = {
+    "bazel%-bin/build",
+    "^spec/"
+  }
+
+}

Makefile

@@ -1,7 +1,7 @@
 OS := $(shell uname | awk '{print tolower($$0)}')
 MACHINE := $(shell uname -m)
 
-DEV_ROCKS = "busted 2.1.2" "busted-htest 1.0.0" "luacheck 1.1.0" "lua-llthreads2 0.1.6" "http 0.4" "ldoc 1.4.6"
+DEV_ROCKS = "busted 2.1.2" "busted-htest 1.0.0" "luacheck 1.1.0" "lua-llthreads2 0.1.6" "http 0.4" "ldoc 1.4.6" "luacov 0.15.0"
 WIN_SCRIPTS = "bin/busted" "bin/kong" "bin/kong-health"
 BUSTED_ARGS ?= -v
 TEST_CMD ?= bin/busted $(BUSTED_ARGS)

spec/01-unit/01-db/01-schema/01-schema_spec.lua

@@ -3,21 +3,6 @@ local cjson  = require "cjson"
 local helpers = require "spec.helpers"
 
 
-local luacov_ok = pcall(require, "luacov")
-if luacov_ok then
-  local busted_it = it
-  -- luacheck: globals it
-  it = function(desc, fn)
-    busted_it(desc, function()
-      local luacov = require("luacov")
-      luacov.init()
-      fn()
-      luacov.save_stats()
-    end)
-  end
-end
-
-
 local SchemaKind = {
   { name = "schema", new = Schema.new, },
   { name = "subschema", new = function(definition)