task: enable thelper and errorlint (#225)

.golangci.yml

@@ -26,7 +26,9 @@ linters-settings:
       - name: error-return
       - name: error-strings
       - name: error-naming
+      - name: errorf
       - name: exported
+      - name: indent-error-flow
       - name: if-return
       - name: increment-decrement
       - name: var-naming
@@ -40,7 +42,9 @@ linters-settings:
       - name: errorf
       - name: empty-block
       - name: superfluous-else
+      - name: struct-tag
       - name: unused-parameter
+      - name: unused-receiver
       - name: unreachable-code
       - name: redefines-builtin-id
   tagliatelle:
@@ -56,54 +60,79 @@ linters:
   # inverted configuration with `enable-all` and `disable` is not scalable during updates of golangci-lint
   disable-all: true
   enable:
-    - bodyclose
-    - deadcode
-    - depguard
-    - dogsled
-    - errcheck
-    - exhaustive
-    - exportloopref
-    - gochecknoinits
-    - gocritic
-    - gocyclo
+    - bodyclose # checks whether HTTP response body is closed successfully [fast: false, auto-fix: false]
+    - deadcode # Finds unused code [fast: false, auto-fix: false]
+    - depguard # Go linter that checks if package imports are in a list of acceptable packages [fast: false, auto-fix: false]
+    - dogsled # Checks assignments with too many blank identifiers (e.g. x, _, _, _, := f()) [fast: true, auto-fix: false]
+    - errcheck # Errcheck is a program for checking for unchecked errors in go programs. These unchecked errors can be critical bugs in some cases [fast: false, auto-fix: false]
+    - errorlint # errorlint is a linter for that can be used to find code that will cause problems with the error wrapping scheme introduced in Go 1.13. [fast: false, auto-fix: false]
+    - exhaustive # check exhaustiveness of enum switch statements [fast: false, auto-fix: false]
+    - exportloopref # checks for pointers to enclosing loop variables [fast: false, auto-fix: false]
+    - gochecknoinits # Checks that no init functions are present in Go code [fast: true, auto-fix: false]
+    - gocritic # Provides many diagnostics that check for bugs, performance and style issues. [fast: false, 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]
-    - gofmt
-    - goimports
-    - goprintffuncname
-    - gosec
-    - gosimple
-    - govet
-    - ineffassign
-    - misspell
-    - nakedret
-    - nolintlint
+    - 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]
+    - goimports # Goimports does everything that gofmt does. Additionally it checks unused imports [fast: true, auto-fix: true]
+    - 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: false, auto-fix: false]
+    - gosimple # Linter for Go source code that specializes in simplifying a code [fast: false, auto-fix: false]
+    - govet # Vet examines Go source code and reports suspicious constructs, such as Printf calls whose arguments do not align with the format string [fast: false, auto-fix: false]
+    - ineffassign # Detects when assignments to existing variables are not used [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]
+    - nolintlint # Reports ill-formed or insufficient nolint directives [fast: true, auto-fix: false]
     - revive # Fast, configurable, extensible, flexible, and beautiful linter for Go. Drop-in replacement of golint. [fast: false, auto-fix: false]
-    - rowserrcheck
-    - staticcheck
-    - structcheck
-    - stylecheck
-    - typecheck
-    - unconvert
-    - unparam
-    - unused
-    - varcheck
-    - whitespace
+    - rowserrcheck # checks whether Err of rows is checked successfully [fast: false, auto-fix: false]
+    - staticcheck  #megacheck): Staticcheck is a go vet on steroids, applying a ton of static analysis checks [fast: false, auto-fix: false]
+    - structcheck # Finds unused struct fields [fast: false, auto-fix: false]
+    - stylecheck # Stylecheck is a replacement for golint [fast: false, auto-fix: false]
+    - thelper # thelper detects golang test helpers without t.Helper() call and checks the consistency of test helpers [fast: false, auto-fix: false]
+    - typecheck # Like the front-end of a Go compiler, parses and type-checks Go code [fast: false, auto-fix: false]
+    - unconvert # Remove unnecessary type conversions [fast: false, auto-fix: false]
+    - unparam # Reports unused function parameters [fast: false, auto-fix: false]
+    - unused # Checks Go code for unused constants, variables, functions and types [fast: false, auto-fix: false]
+    - varcheck # Finds unused global variables and constants [fast: false, auto-fix: false]
+    - whitespace # Tool for detection of leading and trailing whitespace [fast: true, auto-fix: true]
 
   # don't enable:
-  # - asciicheck
-  # - dupl
-  # - funlen
-  # - gochecknoglobals
-  # - gocognit
-  # - goconst
-  # - godot
-  # - godox
-  # - goerr113
-  # - gomnd
-  # - lll
-  # - maligned
-  # - nestif
-  # - noctx
-  # - prealloc
-  # - testpackage
-  # - wsl
+#    - asciicheck # Simple linter to check that your code does not contain non-ASCII identifiers [fast: true, auto-fix: false]
+#    - cyclop # checks function and package cyclomatic complexity [fast: false, auto-fix: false]
+#    - dupl # Tool for code clone detection [fast: true, auto-fix: false]
+#    - durationcheck # check for two durations multiplied together [fast: false, auto-fix: false]
+#    - exhaustivestruct # Checks if all struct's fields are initialized [fast: false, auto-fix: false]
+#    - forbidigo # Forbids identifiers [fast: true, auto-fix: false]
+#    - forcetypeassert # finds forced type assertions [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 [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]
+#    - godox # Tool for detection of FIXME, TODO and other comment keywords [fast: true, auto-fix: false]
+#    - gomnd # An analyzer to detect magic numbers. [fast: true, auto-fix: false]
+#    - goerr113 # Golang linter to check the errors handling expressions [fast: false, auto-fix: false]
+#    - 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]
+#    - gomoddirectives # Manage the use of 'replace', 'retract', and 'excludes' directives in go.mod. [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]
+#    - ifshort # Checks that your code uses short syntax for if-statements whenever possible [fast: true, auto-fix: false]
+#    - importas # Enforces consistent import aliases [fast: false, auto-fix: false]
+#    - interfacer # Linter that suggests narrower interface types [fast: false, auto-fix: false]
+#    - lll # Reports long lines [fast: true, auto-fix: false]
+#    - makezero # Finds slice declarations with non-zero initial length [fast: false, auto-fix: false]
+#    - maligned # Tool to detect Go structs that would take less memory if their fields were sorted [fast: false, auto-fix: false]
+#    - nestif # Reports deeply nested if statements [fast: true, auto-fix: false]
+#    - nilerr # Finds the code that returns nil even if it checks that the error is not nil. [fast: false, 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: false, 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]
+#    - promlinter # Check Prometheus metrics naming via promlint [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: false, auto-fix: false]
+#    - testpackage # linter that makes you use a separate _test package [fast: true, auto-fix: false]
+#    - tparallel # tparallel detects inappropriate usage of t.Parallel() method in your Go test codes [fast: false, auto-fix: false]
+#    - wastedassign # wastedassign finds wasted assignment statements. [fast: false, auto-fix: false]
+#    - wrapcheck # Checks that errors returned from external packages are wrapped [fast: false, auto-fix: false]
+#    - wsl # Whitespace Linter - Forces you to use empty lines! [fast: true, auto-fix: false]

mongodbatlas/mongodbatlas.go

@@ -169,24 +169,6 @@ type ListOptions struct {
 	ItemsPerPage int `url:"itemsPerPage,omitempty"`
 }
 
-// ErrorResponse reports the error caused by an API request.
-type ErrorResponse struct {
-	// HTTP response that caused this error
-	Response *http.Response
-
-	// The error code as specified in https://docs.atlas.mongodb.com/reference/api/api-errors/
-	ErrorCode string `json:"errorCode"`
-
-	// HTTP status code.
-	HTTPCode int `json:"error"`
-
-	// A short description of the error, which is simply the HTTP status phrase.
-	Reason string `json:"reason"`
-
-	// A more detailed description of the error.
-	Detail string `json:"detail,omitempty"`
-}
-
 func (resp *Response) getCurrentPageLink() (*Link, error) {
 	if link := resp.getLinkByRef("self"); link != nil {
 		return link, nil
@@ -222,7 +204,7 @@ func (resp *Response) CurrentPage() (int, error) {
 
 	pageNum, err := strconv.Atoi(pageNumStr)
 	if err != nil {
-		return 0, fmt.Errorf("error getting current page: %s", err)
+		return 0, fmt.Errorf("error getting current page: %w", err)
 	}
 
 	return pageNum, nil
@@ -360,7 +342,7 @@ func (c *Client) NewRequest(ctx context.Context, method, urlStr string, body int
 }
 
 // newEncodedBody returns an ReadWriter object containing the body of the http request.
-func (c *Client) newEncodedBody(body interface{}) (io.Reader, error) {
+func newEncodedBody(body interface{}) (io.Reader, error) {
 	buf := &bytes.Buffer{}
 	enc := json.NewEncoder(buf)
 	enc.SetEscapeHTML(false)
@@ -407,7 +389,7 @@ func (c *Client) newRequest(ctx context.Context, urlStr, method string, body int
 
 	var buf io.Reader
 	if body != nil {
-		if buf, err = c.newEncodedBody(body); err != nil {
+		if buf, err = newEncodedBody(body); err != nil {
 			return nil, err
 		}
 	}
@@ -476,7 +458,7 @@ func (c *Client) Do(ctx context.Context, req *http.Request, v interface{}) (*Res
 			}
 		} else {
 			decErr := json.NewDecoder(resp.Body).Decode(v)
-			if decErr == io.EOF {
+			if errors.Is(decErr, io.EOF) {
 				decErr = nil // ignore EOF errors caused by empty response body
 			}
 			if decErr != nil {
@@ -488,11 +470,35 @@ func (c *Client) Do(ctx context.Context, req *http.Request, v interface{}) (*Res
 	return response, err
 }
 
+// ErrorResponse reports the error caused by an API request.
+type ErrorResponse struct {
+	// Response that caused this error
+	Response *http.Response
+	// ErrorCode is the code as specified in https://docs.atlas.mongodb.com/reference/api/api-errors/
+	ErrorCode string `json:"errorCode"`
+	// HTTPCode status code.
+	HTTPCode int `json:"error"`
+	// Reason is short description of the error, which is simply the HTTP status phrase.
+	Reason string `json:"reason"`
+	// Detail is more detailed description of the error.
+	Detail string `json:"detail,omitempty"`
+}
+
 func (r *ErrorResponse) Error() string {
 	return fmt.Sprintf("%v %v: %d (request %q) %v",
 		r.Response.Request.Method, r.Response.Request.URL, r.Response.StatusCode, r.ErrorCode, r.Detail)
 }
 
+func (r *ErrorResponse) Is(target error) bool {
+	var v *ErrorResponse
+
+	return errors.As(target, &v) &&
+		r.ErrorCode == v.ErrorCode &&
+		r.HTTPCode == v.HTTPCode &&
+		r.Reason == v.Reason &&
+		r.Detail == v.Detail
+}
+
 // CheckResponse checks the API response for errors, and returns them if present. A response is considered an
 // error if it has a status code outside the 200 range. API error responses are expected to have either no response
 // body, or a JSON response body that maps to ErrorResponse. Any other response body will be silently ignored.

mongodbatlas/mongodbatlas_test.go

@@ -17,6 +17,7 @@ package mongodbatlas
 import (
 	"context"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"io/ioutil"
 	"net/http"
@@ -73,49 +74,41 @@ func setup() (client *Client, mux *http.ServeMux, teardown func()) {
 }
 
 func testMethod(t *testing.T, r *http.Request, expected string) {
+	t.Helper()
 	if expected != r.Method {
 		t.Errorf("Request method = %v, expected %v", r.Method, expected)
 	}
 }
 
 func testURLParseError(t *testing.T, err error) {
+	t.Helper()
 	if err == nil {
 		t.Errorf("Expected error to be returned")
 	}
-	if err, ok := err.(*url.Error); !ok || err.Op != "parse" {
+	var target *url.Error
+	if errors.As(err, &target) && target.Op != "parse" {
 		t.Errorf("Expected URL parse error, got %+v", err)
 	}
 }
 
-func testClientServices(t *testing.T, c *Client) {
-	services := []string{}
-
-	cp := reflect.ValueOf(c)
-	cv := reflect.Indirect(cp)
-
-	for _, s := range services {
-		if cv.FieldByName(s).IsNil() {
-			t.Errorf("c.%s shouldn't be nil", s)
-		}
-	}
-}
-
 func testClientDefaultBaseURL(t *testing.T, c *Client) {
+	t.Helper()
 	if c.BaseURL == nil || c.BaseURL.String() != defaultBaseURL {
 		t.Errorf("NewClient BaseURL = %v, expected %v", c.BaseURL, defaultBaseURL)
 	}
 }
 
 func testClientDefaultUserAgent(t *testing.T, c *Client) {
+	t.Helper()
 	if c.UserAgent != userAgent {
 		t.Errorf("NewClient UserAgent = %v, expected %v", c.UserAgent, userAgent)
 	}
 }
 
 func testClientDefaults(t *testing.T, c *Client) {
+	t.Helper()
 	testClientDefaultBaseURL(t, c)
 	testClientDefaultUserAgent(t, c)
-	testClientServices(t, c)
 }
 
 func TestNewClient(t *testing.T) {
@@ -407,7 +400,8 @@ func TestDo_redirectLoop(t *testing.T) {
 	if err == nil {
 		t.Error("Expected error to be returned.")
 	}
-	if err, ok := err.(*url.Error); !ok {
+	var target *url.Error
+	if !errors.As(err, &target) {
 		t.Errorf("Expected a URL error; got %#v.", err)
 	}
 }
@@ -439,9 +433,8 @@ func TestCheckResponse(t *testing.T) {
 			),
 		),
 	}
-	err := CheckResponse(res).(*ErrorResponse)
-
-	if err == nil {
+	var target *ErrorResponse
+	if !errors.As(CheckResponse(res), &target) {
 		t.Fatalf("Expected error response.")
 	}
 
@@ -452,8 +445,8 @@ func TestCheckResponse(t *testing.T) {
 		Reason:    "Conflict",
 		Detail:    `A group with name "Test" already exists`,
 	}
-	if !reflect.DeepEqual(err, expected) {
-		t.Errorf("Error = %#v, expected %#v", err, expected)
+	if !errors.Is(target, expected) {
+		t.Errorf("Got = %#v, expected %#v", target, expected)
 	}
 }
 
@@ -465,17 +458,16 @@ func TestCheckResponse_noBody(t *testing.T) {
 		StatusCode: http.StatusBadRequest,
 		Body:       ioutil.NopCloser(strings.NewReader("")),
 	}
-	err := CheckResponse(res).(*ErrorResponse)
-
-	if err == nil {
+	var target *ErrorResponse
+	if !errors.As(CheckResponse(res), &target) {
 		t.Errorf("Expected error response.")
 	}
 
 	expected := &ErrorResponse{
 		Response: res,
 	}
-	if !reflect.DeepEqual(err, expected) {
-		t.Errorf("Error = %#v, expected %#v", err, expected)
+	if !errors.Is(target, expected) {
+		t.Errorf("Got = %#v, expected %#v", target, expected)
 	}
 }
 
@@ -563,6 +555,7 @@ func TestCustomBaseURL_badURL(t *testing.T) {
 }
 
 func checkCurrentPage(t *testing.T, resp *Response, expectedPage int) { //nolint:unparam // currently we always use expectedPage with value 2 but that may change
+	t.Helper()
 	p, err := resp.CurrentPage()
 	if err != nil {
 		t.Fatal(err)