golangci: enable new linters

Only newly added code will trigger these linter checks.

.golangci.yml

@@ -53,6 +53,16 @@ linters-settings:
     # Tab width in spaces.
     tab-width: 8
 
+  funlen:
+    # Checks the number of lines in a function.
+    # If lower than 0, disable the check.
+    # Default: 60
+    lines: 60 
+    # Checks the number of statements in a function.
+    # Default: 40
+    statements: 40
+
+
 linters:
   enable-all: true
   disable:
@@ -65,18 +75,6 @@ linters:
   # We want to allow TODOs.
   - godox
 
-  # We have long functions, especially in tests. Moving or renaming those would
-  # trigger funlen problems that we may not want to solve at that time.
-  - funlen
-
-  # Disable for now as we haven't yet tuned the sensitivity to our codebase
-  # yet. Enabling by default for example, would also force new contributors to
-  # potentially extensively refactor code, when they want to smaller change to
-  # land.
-  - gocyclo
-  - gocognit
-  - cyclop
-
   # Instances of table driven tests that don't pre-allocate shouldn't trigger
   # the linter.
   - prealloc
@@ -84,46 +82,23 @@ linters:
   # Init functions are used by loggers throughout the codebase.
   - gochecknoinits
   
-  # Causes stack overflow, see https://github.com/polyfloyd/go-errorlint/issues/19.
-  - errorlint
-
   # Deprecated linters. See https://golangci-lint.run/usage/linters/.
   - interfacer
   - golint
   - maligned
   - scopelint
-  
-  # New linters that need a code adjustment first.
-  - wrapcheck
-  - nolintlint
-  - paralleltest
-  - tparallel
-  - testpackage
-  - gofumpt
-  - gomoddirectives
-  - ireturn
-  - maintidx
-  - nlreturn
-  - dogsled
-  - gci
-  - containedctx
-  - contextcheck
-  - errname
   - exhaustivestruct
-  - exhaustruct
+  - bodyclose
-  - goerr113
+  - contextcheck
-  - gomnd
-  - ifshort
-  - noctx
-  - nestif
-  - wsl
-  - exhaustive
-  - forcetypeassert
   - nilerr
-  - nilnil
+  - noctx
-  - stylecheck
+  - rowserrcheck
-  - thelper
+  - sqlclosecheck
-
+  - structcheck
+  - tparallel
+  - unparam
+  - wastedassign
+  
 issues:
   # Only show newly introduced problems.
   new-from-rev: 8c66353e4c02329abdacb5a8df29998035ec2e24
@@ -134,9 +109,11 @@ issues:
     - path: _test\.go
       linters:
         - gosec
+        - funlen
     - path: test*
       linters:
         - gosec
+        - funlen
 
     # Allow duplicated code and fmt.Printf() in DB migrations.
     - path: channeldb/migration*
@@ -172,3 +149,5 @@ issues:
         - deadcode
         - unparam
         - govet
+        # itest case can be very long so we disable long function check.
+        - funlen