Add linting while ignoring legacy issues for now

Fixes #11

.github/workflows/lint.yml

@@ -0,0 +1,48 @@
+name: Lint
+
+on:
+  # Enable manually triggering this workflow via the API or web UI
+  workflow_dispatch:
+  push:
+    branches:
+      - main
+    tags:
+      - v*
+  pull_request:
+
+jobs:
+  check-modules:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v3
+      - name: Install Go
+        uses: actions/setup-go@v3
+        with:
+          go-version: 1.18.x
+      - name: Check module dependencies
+        run: |
+          go version
+          test -z "$(go mod tidy && git status go.* --porcelain)"
+          go mod verify
+
+  run-golangci:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v3
+      - name: Install Go
+        uses: actions/setup-go@v3
+        with:
+          # TODO up this to 1.18.x when we update teh version of golangci-lint to latest
+          go-version: 1.17.x
+      - name: Retrieve golangci-lint version
+        run: |
+          echo "::set-output name=Version::$(head -n 1 "${GITHUB_WORKSPACE}/.golangci.yml" | tr -d '# ')"
+        id: version
+      - name: golangci-lint
+        uses: golangci/golangci-lint-action@v3
+        with:
+          # Required: the version of golangci-lint is required and must be specified without patch version: we always use the latest patch version.
+          version: ${{ steps.version.outputs.Version }}
+          only-new-issues: true

.golangci.yml

@@ -0,0 +1,77 @@
+# v1.43.0
+# Please don't remove the first line. It is used in CI to determine the golangci version
+run:
+  deadline: 5m
+
+issues:
+  # Maximum issues count per one linter. Set to 0 to disable. Default is 50.
+  max-issues-per-linter: 0
+  # Maximum count of issues with the same text. Set to 0 to disable. Default is 3.
+  max-same-issues: 0
+
+  # We want to try and improve the comments in the k6 codebase, so individual
+  # non-golint items from the default exclusion list will gradually be added
+  # to the exclude-rules below
+  exclude-use-default: false
+
+  exclude-rules:
+    # Exclude duplicate code and function length and complexity checking in test
+    # files (due to common repeats and long functions in test code)
+    - path: _(test|gen)\.go
+      linters:
+        - cyclop
+        - dupl
+        - funlen
+        - gocognit
+        - lll
+    - linters:
+        - paralleltest # false positive: https://github.com/kunwardeep/paralleltest/issues/8.
+      text: "does not use range value in test Run"
+
+linters-settings:
+  cyclop:
+    max-complexity: 25
+  dupl:
+    threshold: 150
+  exhaustive:
+    default-signifies-exhaustive: true
+  funlen:
+    lines: 80
+    statements: 60
+  goconst:
+    min-len: 10
+    min-occurrences: 4
+  govet:
+    check-shadowing: true
+  maligned:
+    suggest-new: true
+  nolintlint:
+    # Disable to ensure that nolint directives don't have a leading space. Default is true.
+    allow-leading-space: false
+
+linters:
+  enable-all: true
+  disable:
+    - exhaustivestruct
+    - gci
+    - gochecknoinits
+    - gocyclo # replaced by cyclop since it also calculates the package complexity
+    - godot
+    - godox
+    - goerr113 # most of the errors here are meant for humans
+    - goheader
+    - golint # this linter is deprecated
+    - gomnd
+    - gomodguard
+    - interfacer # deprecated
+    - ireturn
+    - maligned # replaced by govet 'fieldalignment'
+    - nlreturn
+    - scopelint # deprecated, replaced by exportloopref
+    - tagliatelle
+    - testpackage
+    - thelper
+    - varnamelen # disabled before the final decision in (https://github.com/grafana/k6/pull/2323)
+    - wrapcheck # a little bit too much for k6, maybe after https://github.com/tomarrell/wrapcheck/issues/2 is fixed
+    - wsl
+  fast: false