Fix error handling conforms to golangci-lint standards

.env.docker

@@ -4,4 +4,4 @@ MYSQL_DATABASE=db
 MYSQL_PASSWORD=password
 MYSQL_PORT=3306
 DB_HOSTNAME=db
-API_URL=http://api:8080
+API_URL=http://api:8081

api/.golangci.yml

@@ -1,28 +1,145 @@
-linters:
-  enable:
-    - errcheck        
-    - govet           
-    - staticcheck     
-    - gofmt           
-    - goimports       
+# https://golangci-lint.run/usage/configuration/
+
 
 run:
-  timeout: 5m         
-  tests: true         
+  issues-exit-code: 1
+  tests: true
+  timeout: 1m
+  # skip-dirs:
+  #   - .github
+  #   - .githook
+  #   - vendor
+
+#  # by default isn't set. If set we pass it to "go list -mod={option}". From "go help modules":
+#  # If invoked with -mod=readonly, the go command is disallowed from the implicit
+#  # automatic updating of go.mod described above. Instead, it fails when any changes
+#  # to go.mod are needed. This setting is most useful to check that go.mod does
+#  # not need updates, such as in a continuous integration and testing system.
+#  # If invoked with -mod=vendor, the go command assumes that the vendor
+#  # directory holds the correct copies of dependencies and ignores
+#  # the dependency descriptions in go.mod.
+#  modules-download-mode: readonly|release|vendor
+#  modules-download-mode: vendor
 
-issues:
-  exclude-use-default: false
-  exclude:
-    - "Error return value of"
-    - "SA4006"        
+# output:
+  # colored-line-number|line-number|json|tab|checkstyle|code-climate, default is "colored-line-number"
+  # format: colored-line-number
+
+## all available settings of specific linters
+#linters-settings:
+#  lll:
+#    # max line length, lines longer will be reported. Default is 120.
+#    # '\t' is counted as 1 character by default, and can be changed with the tab-width option
+#    line-length: 120
+#    # tab width in spaces. Default to 1.
+#    tab-width: 1
+#  nakedret:
+#    # make an issue if func has more lines of code than this setting and it has naked returns; default is 30
+#    max-func-lines: 30
+#  prealloc:
+#    # XXX: we don't recommend using this linter before doing performance profiling.
+#    # For most programs usage of prealloc will be a premature optimization.
+#
+#    # Report preallocation suggestions only on simple loops that have no returns/breaks/continues/gotos in them.
+#    # True by default.
+#    simple: true
+#    range-loops: true # Report preallocation suggestions on range loops, true by default
+#    for-loops: false # Report preallocation suggestions on for loops, false by default
+#  nolintlint:
+#    # Enable to ensure that nolint directives are all used. Default is true.
+#    allow-unused: false
+#    # Disable to ensure that nolint directives don't have a leading space. Default is true.
+#    allow-leading-space: true
+#    # Exclude following linters from requiring an explanation.  Default is [].
+#    allow-no-explanation: []
+#    # Enable to require an explanation of nonzero length after each nolint directive. Default is false.
+#    require-explanation: true
+#    # Enable to require nolint directives to mention the specific linter being suppressed. Default is false.
+#    require-specific: true
 
 linters-settings:
-  errcheck:
-    exclude-functions:
-      - fmt.Println
-      - bytes.Buffer.WriteString  
+  gocognit:
+    min-complexity: 10
+  gocyclo:
+    min-complexity: 10
   gofmt:
-    simplify: true    
-  staticcheck:
-    checks:           
-      - all           
+    simplify: true
+#  maligned:
+#    suggest-new: true
+  misspell:
+    locale: US
+#    ignore-words:
+#      - someword
+  whitespace:
+    multi-if: false   # Enforces newlines (or comments) after every multi-line if statement
+    multi-func: false # Enforces newlines (or comments) after every multi-line function signature
+
+linters:
+  disable:
+    - godox
+  enable:
+    - errcheck             # Errcheck is a program for checking for unchecked errors in go programs. These unchecked errors can be critical bugs in some cases [fast: true, auto-fix: false]
+    - gosimple             # Linter for Go source code that specializes in simplifying a code [fast: true, auto-fix: false]
+    - unused
+    - copyloopvar
+    - revive
+    - govet                # Vet examines Go source code and reports suspicious constructs, such as Printf calls whose arguments do not align with the format string [fast: true, auto-fix: false]
+    - ineffassign          # Detects when assignments to existing variables are not used [fast: true, auto-fix: false]
+    - staticcheck          # Staticcheck is a go vet on steroids, applying a ton of static analysis checks [fast: true, auto-fix: false]
+    - typecheck            # Like the front-end of a Go compiler, parses and type-checks Go code [fast: true, auto-fix: false]
+    - unused               # Checks Go code for unused constants, variables, functions and types [fast: false, auto-fix: false]
+    - asciicheck           # Simple linter to check that your code does not contain non-ASCII identifiers [fast: true, auto-fix: false]
+    - bodyclose            # checks whether HTTP response body is closed successfully [fast: true, auto-fix: false]
+    - depguard             # Go linter that checks if package imports are in a list of acceptable packages [fast: true, auto-fix: false]
+    - dogsled              # Checks assignments with too many blank identifiers (e.g. x, _, _, _, := f()) [fast: true, auto-fix: false]
+    - dupl                 # Tool for code clone detection [fast: true, auto-fix: false]
+    - errorlint            # go-errorlint is a source code linter for Go software that can be used to find code that will cause problemswith the error wrapping scheme introduced in Go 1.13. [fast: true, auto-fix: false]
+    - exhaustive           # check exhaustiveness of enum switch statements [fast: true, auto-fix: false]
+#    - exhaustivestruct     # Checks if all struct's fields are initialized [fast: true, auto-fix: false]
+    - exportloopref        # checks for pointers to enclosing loop variables [fast: true, auto-fix: false]
+    - forbidigo            # Forbids identifiers [fast: true, auto-fix: false]
+#    - funlen               # Tool for detection of long functions [fast: true, auto-fix: false]
+    - gci                  # Gci control golang package import order and make it always deterministic. [fast: true, auto-fix: true]
+    - gochecknoglobals     # check that no global variables exist
+    - gochecknoinits       # Checks that no init functions are present in Go code [fast: true, auto-fix: false]
+    - gocognit             # Computes and checks the cognitive complexity of functions [fast: true, auto-fix: false]
+    - goconst              # Finds repeated strings that could be replaced by a constant [fast: true, auto-fix: false]
+    - gocritic             # The most opinionated Go source code linter [fast: true, auto-fix: false]
+    - gocyclo              # Computes and checks the cyclomatic complexity of functions [fast: true, auto-fix: false]
+    - godot                # Check if comments end in a period [fast: true, auto-fix: true]
+#    - godox                # Tool for detection of FIXME, TODO and other comment keywords [fast: true, auto-fix: false]
+#    - goerr113             # Golang linter to check the errors handling expressions [fast: true, auto-fix: false]
+    - gofmt                # Gofmt checks whether code was gofmt-ed. By default this tool runs with -s option to check for code simplification [fast: true, auto-fix: true]
+#    - gofumpt              # Gofumpt checks whether code was gofumpt-ed. [fast: true, auto-fix: true]
+    - goheader             # Checks is file header matches to pattern [fast: true, auto-fix: false]
+    - goimports            # Goimports does everything that gofmt does. Additionally it checks unused imports [fast: true, auto-fix: true]
+#    - gomnd                # An analyzer to detect magic numbers. [fast: true, auto-fix: false]
+    - gomodguard           # Allow and block list linter for direct Go module dependencies. This is different from depguard where there are different block types for example version constraints and module recommendations. [fast: true, auto-fix: false]
+    - goprintffuncname     # Checks that printf-like functions are named with `f` at the end [fast: true, auto-fix: false]
+    - gosec                # Inspects source code for security problems [fast: true, auto-fix: false]
+#    - ifshort              # Checks that your code uses short syntax for if-statements whenever possible [fast: true, auto-fix: false]
+#    - interfacer           # Linter that suggests narrower interface types [fast: true, auto-fix: false]
+#    - lll                  # Reports long lines [fast: true, auto-fix: false]
+    - makezero             # Finds slice declarations with non-zero initial length [fast: true, auto-fix: false]
+#    - maligned             # Tool to detect Go structs that would take less memory if their fields were sorted [fast: true, auto-fix: false]
+    - misspell             # Finds commonly misspelled English words in comments [fast: true, auto-fix: true]
+    - nakedret             # Finds naked returns in functions greater than a specified function length [fast: true, auto-fix: false]
+    - nestif               # Reports deeply nested if statements [fast: true, auto-fix: false]
+#    - nlreturn             # nlreturn checks for a new line before return and branch statements to increase code clarity [fast: true, auto-fix: false]
+    - noctx                # noctx finds sending http request without context.Context [fast: true, auto-fix: false]
+    - nolintlint           # Reports ill-formed or insufficient nolint directives [fast: true, auto-fix: false]
+#    - paralleltest         # paralleltest detects missing usage of t.Parallel() method in your Go test [fast: true, auto-fix: false]
+    - prealloc             # Finds slice declarations that could potentially be preallocated [fast: true, auto-fix: false]
+    - predeclared          # find code that shadows one of Go's predeclared identifiers [fast: true, auto-fix: false]
+    - rowserrcheck         # checks whether Err of rows is checked successfully [fast: true, auto-fix: false]
+#    - scopelint            # Scopelint checks for unpinned variables in go programs [fast: true, auto-fix: false]
+    - sqlclosecheck        # Checks that sql.Rows and sql.Stmt are closed. [fast: true, auto-fix: false]
+    - stylecheck           # Stylecheck is a replacement for golint [fast: true, auto-fix: false]
+#    - testpackage          # linter that makes you use a separate _test package [fast: true, auto-fix: false]
+    - thelper              # thelper detects golang test helpers without t.Helper() call and checks the consistency of test helpers [fast: true, auto-fix: false]
+    - tparallel            # tparallel detects inappropriate usage of t.Parallel() method in your Go test codes [fast: true, auto-fix: false]
+    - unconvert            # Remove unnecessary type conversions [fast: true, auto-fix: false]
+    - unparam              # Reports unused function parameters [fast: true, auto-fix: false]
+    - whitespace           # Tool for detection of leading and trailing whitespace [fast: true, auto-fix: true]
+    - wrapcheck            # Checks that errors returned from external packages are wrapped [fast: true, auto-fix: false]
+    - wsl                  # Whitespace Linter - Forces you to use empty lines! [fast: true, auto-fix: false]

api/db_service_test.go

@@ -15,7 +15,7 @@ type TestDBService struct {
 func NewTestDBService() (*TestDBService, error) {
 	db, mock, err := sqlmock.New()
 	if err != nil {
-		return nil, fmt.Errorf("an error '%s' was not expected when opening a stub database connection", err)
+		return nil, fmt.Errorf("an error occurred when opening a stub database connection: %w", err)
 	}
 
 	return &TestDBService{