2 files changed, 247 insertions, 0 deletions
diff --git a/vendor/github.com/tomarrell/wrapcheck/LICENSE b/vendor/github.com/tomarrell/wrapcheck/LICENSE
new file mode 100644
index 000000000..b5d9d30d3
--- /dev/null
+++ b/vendor/github.com/tomarrell/wrapcheck/LICENSE
@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2020 Tom Arrell
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
diff --git a/vendor/github.com/tomarrell/wrapcheck/wrapcheck/wrapcheck.go b/vendor/github.com/tomarrell/wrapcheck/wrapcheck/wrapcheck.go
new file mode 100644
index 000000000..e249a7ed2
--- /dev/null
+++ b/vendor/github.com/tomarrell/wrapcheck/wrapcheck/wrapcheck.go
@@ -0,0 +1,226 @@
+package wrapcheck
+
+import (
+	"go/ast"
+	"go/types"
+
+	"golang.org/x/tools/go/analysis"
+)
+
+var ignoredIDs = []string{
+	"func fmt.Errorf(format string, a ...interface{}) error",
+	"func errors.New(text string) error",
+	"func errors.Unwrap(err error) error",
+}
+
+var Analyzer = &analysis.Analyzer{
+	Name: "wrapcheck",
+	Doc:  "Checks that errors returned from external packages are wrapped",
+	Run:  run,
+}
+
+func run(pass *analysis.Pass) (interface{}, error) {
+	for _, file := range pass.Files {
+		ast.Inspect(file, func(n ast.Node) bool {
+			if _, ok := n.(*ast.AssignStmt); ok {
+				return true
+			}
+
+			ret, ok := n.(*ast.ReturnStmt)
+			if !ok {
+				return true
+			}
+
+			if len(ret.Results) < 1 {
+				return true
+			}
+
+			// Iterate over the values to be returned looking for errors
+			for _, expr := range ret.Results {
+				if !isError(pass.TypesInfo.TypeOf(expr)) {
+					continue
+				}
+
+				ident, ok := expr.(*ast.Ident)
+				if !ok {
+					return true
+				}
+
+				var (
+					call *ast.CallExpr
+				)
+
+				// Attempt to find the most recent short assign
+				if shortAss := prevErrAssign(pass, file, ident); shortAss != nil {
+					call, ok = shortAss.Rhs[0].(*ast.CallExpr)
+					if !ok {
+						return true
+					}
+				} else if isUnresolved(file, ident) {
+					// TODO Check if the identifier is unresolved, and try to resolve it in
+					// another file.
+					return true
+				} else {
+					// Check for ValueSpec nodes in order to locate a possible var
+					// declaration.
+					if ident.Obj == nil {
+						return true
+					}
+
+					vSpec, ok := ident.Obj.Decl.(*ast.ValueSpec)
+					if !ok {
+						// We couldn't find a short or var assign for this error return.
+						// This is an error. Where did this identifier come from? Possibly a
+						// function param.
+						//
+						// TODO decide how to handle this case, whether to follow function
+						// param back, or assert wrapping at call site.
+
+						return true
+					}
+
+					if len(vSpec.Values) < 1 {
+						return true
+					}
+
+					call, ok = vSpec.Values[0].(*ast.CallExpr)
+					if !ok {
+						return true
+					}
+				}
+
+				// Make sure there is a call identified as producing the error being
+				// returned, otherwise just bail
+				if call == nil {
+					return true
+				}
+
+				sel, ok := call.Fun.(*ast.SelectorExpr)
+				if !ok {
+					return true
+				}
+
+				// Check if the underlying type of the "x" in x.y.z is an interface, as
+				// errors returned from interface types should be wrapped.
+				if isInterface(pass, sel, ident) {
+					pass.Reportf(ident.NamePos, "error returned from interface method should be wrapped")
+					return true
+				}
+
+				// Check whether the function being called comes from another package,
+				// as functions called across package boundaries which returns errors
+				// should be wrapped
+				if isFromOtherPkg(pass, sel, ident) {
+					pass.Reportf(ident.NamePos, "error returned from external package is unwrapped")
+					return true
+				}
+			}
+
+			return true
+		})
+	}
+
+	return nil, nil
+}
+
+// isInterface returns whether the function call is one defined on an interface.
+func isInterface(pass *analysis.Pass, sel *ast.SelectorExpr, ident *ast.Ident) bool {
+	_, ok := pass.TypesInfo.TypeOf(sel.X).Underlying().(*types.Interface)
+
+	return ok
+}
+
+func isFromOtherPkg(pass *analysis.Pass, sel *ast.SelectorExpr, ident *ast.Ident) bool {
+	// The package of the function that we are calling which returns the error
+	fn := pass.TypesInfo.ObjectOf(sel.Sel)
+
+	// If it's not a package name, then we should check the selector to make sure
+	// that it's an identifier from the same package
+	if pass.Pkg.Path() == fn.Pkg().Path() {
+		return false
+	} else if contains(ignoredIDs, fn.String()) {
+		return false
+	}
+
+	return true
+}
+
+// prevErrAssign traverses the AST of a file looking for the most recent
+// assignment to an error declaration which is specified by the returnIdent
+// identifier.
+//
+// This only returns short form assignments and reassignments, e.g. `:=` and
+// `=`. This does not include `var` statements. This function will return nil if
+// the only declaration is a `var` (aka ValueSpec) declaration.
+func prevErrAssign(pass *analysis.Pass, file *ast.File, returnIdent *ast.Ident) *ast.AssignStmt {
+	// A slice containing all the assignments which contain an identifer
+	// referring to the source declaration of the error. This is to catch
+	// cases where err is defined once, and then reassigned multiple times
+	// within the same block. In these cases, we should check the method of
+	// the most recent call.
+	var assigns []*ast.AssignStmt
+
+	// Find all assignments which have the same declaration
+	ast.Inspect(file, func(n ast.Node) bool {
+		if ass, ok := n.(*ast.AssignStmt); ok {
+			for _, expr := range ass.Lhs {
+				if !isError(pass.TypesInfo.TypeOf(expr)) {
+					continue
+				}
+				if assIdent, ok := expr.(*ast.Ident); ok {
+					if assIdent.Obj == nil || returnIdent.Obj == nil {
+						// If we can't find the Obj for one of the identifiers, just skip
+						// it.
+						return true
+					} else if assIdent.Obj.Decl == returnIdent.Obj.Decl {
+						assigns = append(assigns, ass)
+					}
+				}
+			}
+		}
+
+		return true
+	})
+
+	// Iterate through the assignments, comparing the token positions to
+	// find the assignment that directly precedes the return position
+	var mostRecentAssign *ast.AssignStmt
+
+	for _, ass := range assigns {
+		if ass.Pos() > returnIdent.Pos() {
+			break
+		}
+		mostRecentAssign = ass
+	}
+
+	return mostRecentAssign
+}
+
+func contains(slice []string, el string) bool {
+	for _, s := range slice {
+		if s == el {
+			return true
+		}
+	}
+
+	return false
+}
+
+// isError returns whether or not the provided type interface is an error
+func isError(typ types.Type) bool {
+	if typ == nil {
+		return false
+	}
+
+	return typ.String() == "error"
+}
+
+func isUnresolved(file *ast.File, ident *ast.Ident) bool {
+	for _, unresolvedIdent := range file.Unresolved {
+		if unresolvedIdent.Pos() == ident.Pos() {
+			return true
+		}
+	}
+
+	return false
+}