eval_variable_test.go

package terraform

import (
	"fmt"
	"strings"
	"testing"

	"github.com/hashicorp/hcl/v2"
	"github.com/zclconf/go-cty/cty"

	"github.com/hashicorp/terraform/internal/addrs"
	"github.com/hashicorp/terraform/internal/lang"
	"github.com/hashicorp/terraform/internal/lang/marks"
	"github.com/hashicorp/terraform/internal/tfdiags"
)

func TestPrepareFinalInputVariableValue(t *testing.T) {
	// This is just a concise way to define a bunch of *configs.Variable
	// objects to use in our tests below. We're only going to decode this
	// config, not fully evaluate it.
	cfgSrc := `
		variable "nullable_required" {
		}
		variable "nullable_optional_default_string" {
			default = "hello"
		}
		variable "nullable_optional_default_null" {
			default = null
		}
		variable "constrained_string_nullable_required" {
			type = string
		}
		variable "constrained_string_nullable_optional_default_string" {
			type    = string
			default = "hello"
		}
		variable "constrained_string_nullable_optional_default_bool" {
			type    = string
			default = true
		}
		variable "constrained_string_nullable_optional_default_null" {
			type    = string
			default = null
		}
		variable "required" {
			nullable = false
		}
		variable "optional_default_string" {
			nullable = false
			default  = "hello"
		}
		variable "constrained_string_required" {
			nullable = false
			type     = string
		}
		variable "constrained_string_optional_default_string" {
			nullable = false
			type     = string
			default  = "hello"
		}
		variable "constrained_string_optional_default_bool" {
			nullable = false
			type     = string
			default  = true
		}
		variable "constrained_string_sensitive_required" {
			sensitive = true
			nullable  = false
			type      = string
		}
	`
	cfg := testModuleInline(t, map[string]string{
		"main.tf": cfgSrc,
	})
	variableConfigs := cfg.Module.Variables

	// Because we loaded our pseudo-module from a temporary file, the
	// declaration source ranges will have unpredictable filenames. We'll
	// fix that here just to make things easier below.
	for _, vc := range variableConfigs {
		vc.DeclRange.Filename = "main.tf"
	}

	tests := []struct {
		varName string
		given   cty.Value
		want    cty.Value
		wantErr string
	}{
		// nullable_required
		{
			"nullable_required",
			cty.NilVal,
			cty.UnknownVal(cty.DynamicPseudoType),
			`Required variable not set: The variable "nullable_required" is required, but is not set.`,
		},
		{
			"nullable_required",
			cty.NullVal(cty.DynamicPseudoType),
			cty.NullVal(cty.DynamicPseudoType),
			``, // "required" for a nullable variable means only that it must be set, even if it's set to null
		},
		{
			"nullable_required",
			cty.StringVal("ahoy"),
			cty.StringVal("ahoy"),
			``,
		},
		{
			"nullable_required",
			cty.UnknownVal(cty.String),
			cty.UnknownVal(cty.String),
			``,
		},

		// nullable_optional_default_string
		{
			"nullable_optional_default_string",
			cty.NilVal,
			cty.StringVal("hello"), // the declared default value
			``,
		},
		{
			"nullable_optional_default_string",
			cty.NullVal(cty.DynamicPseudoType),
			cty.NullVal(cty.DynamicPseudoType), // nullable variables can be really set to null, masking the default
			``,
		},
		{
			"nullable_optional_default_string",
			cty.StringVal("ahoy"),
			cty.StringVal("ahoy"),
			``,
		},
		{
			"nullable_optional_default_string",
			cty.UnknownVal(cty.String),
			cty.UnknownVal(cty.String),
			``,
		},

		// nullable_optional_default_null
		{
			"nullable_optional_default_null",
			cty.NilVal,
			cty.NullVal(cty.DynamicPseudoType), // the declared default value
			``,
		},
		{
			"nullable_optional_default_null",
			cty.NullVal(cty.String),
			cty.NullVal(cty.String), // nullable variables can be really set to null, masking the default
			``,
		},
		{
			"nullable_optional_default_null",
			cty.StringVal("ahoy"),
			cty.StringVal("ahoy"),
			``,
		},
		{
			"nullable_optional_default_null",
			cty.UnknownVal(cty.String),
			cty.UnknownVal(cty.String),
			``,
		},

		// constrained_string_nullable_required
		{
			"constrained_string_nullable_required",
			cty.NilVal,
			cty.UnknownVal(cty.String),
			`Required variable not set: The variable "constrained_string_nullable_required" is required, but is not set.`,
		},
		{
			"constrained_string_nullable_required",
			cty.NullVal(cty.DynamicPseudoType),
			cty.NullVal(cty.String), // the null value still gets converted to match the type constraint
			``,                      // "required" for a nullable variable means only that it must be set, even if it's set to null
		},
		{
			"constrained_string_nullable_required",
			cty.StringVal("ahoy"),
			cty.StringVal("ahoy"),
			``,
		},
		{
			"constrained_string_nullable_required",
			cty.UnknownVal(cty.String),
			cty.UnknownVal(cty.String),
			``,
		},

		// constrained_string_nullable_optional_default_string
		{
			"constrained_string_nullable_optional_default_string",
			cty.NilVal,
			cty.StringVal("hello"), // the declared default value
			``,
		},
		{
			"constrained_string_nullable_optional_default_string",
			cty.NullVal(cty.DynamicPseudoType),
			cty.NullVal(cty.String), // nullable variables can be really set to null, masking the default
			``,
		},
		{
			"constrained_string_nullable_optional_default_string",
			cty.StringVal("ahoy"),
			cty.StringVal("ahoy"),
			``,
		},
		{
			"constrained_string_nullable_optional_default_string",
			cty.UnknownVal(cty.String),
			cty.UnknownVal(cty.String),
			``,
		},

		// constrained_string_nullable_optional_default_bool
		{
			"constrained_string_nullable_optional_default_bool",
			cty.NilVal,
			cty.StringVal("true"), // the declared default value, automatically converted to match type constraint
			``,
		},
		{
			"constrained_string_nullable_optional_default_bool",
			cty.NullVal(cty.DynamicPseudoType),
			cty.NullVal(cty.String), // nullable variables can be really set to null, masking the default
			``,
		},
		{
			"constrained_string_nullable_optional_default_bool",
			cty.StringVal("ahoy"),
			cty.StringVal("ahoy"),
			``,
		},
		{
			"constrained_string_nullable_optional_default_bool",
			cty.UnknownVal(cty.String),
			cty.UnknownVal(cty.String),
			``,
		},

		// constrained_string_nullable_optional_default_null
		{
			"constrained_string_nullable_optional_default_null",
			cty.NilVal,
			cty.NullVal(cty.String),
			``,
		},
		{
			"constrained_string_nullable_optional_default_null",
			cty.NullVal(cty.DynamicPseudoType),
			cty.NullVal(cty.String),
			``,
		},
		{
			"constrained_string_nullable_optional_default_null",
			cty.StringVal("ahoy"),
			cty.StringVal("ahoy"),
			``,
		},
		{
			"constrained_string_nullable_optional_default_null",
			cty.UnknownVal(cty.String),
			cty.UnknownVal(cty.String),
			``,
		},

		// required
		{
			"required",
			cty.NilVal,
			cty.UnknownVal(cty.DynamicPseudoType),
			`Required variable not set: The variable "required" is required, but is not set.`,
		},
		{
			"required",
			cty.NullVal(cty.DynamicPseudoType),
			cty.UnknownVal(cty.DynamicPseudoType),
			`Required variable not set: Unsuitable value for var.required set from outside of the configuration: required variable may not be set to null.`,
		},
		{
			"required",
			cty.StringVal("ahoy"),
			cty.StringVal("ahoy"),
			``,
		},
		{
			"required",
			cty.UnknownVal(cty.String),
			cty.UnknownVal(cty.String),
			``,
		},

		// optional_default_string
		{
			"optional_default_string",
			cty.NilVal,
			cty.StringVal("hello"), // the declared default value
			``,
		},
		{
			"optional_default_string",
			cty.NullVal(cty.DynamicPseudoType),
			cty.StringVal("hello"), // the declared default value
			``,
		},
		{
			"optional_default_string",
			cty.StringVal("ahoy"),
			cty.StringVal("ahoy"),
			``,
		},
		{
			"optional_default_string",
			cty.UnknownVal(cty.String),
			cty.UnknownVal(cty.String),
			``,
		},

		// constrained_string_required
		{
			"constrained_string_required",
			cty.NilVal,
			cty.UnknownVal(cty.String),
			`Required variable not set: The variable "constrained_string_required" is required, but is not set.`,
		},
		{
			"constrained_string_required",
			cty.NullVal(cty.DynamicPseudoType),
			cty.UnknownVal(cty.String),
			`Required variable not set: Unsuitable value for var.constrained_string_required set from outside of the configuration: required variable may not be set to null.`,
		},
		{
			"constrained_string_required",
			cty.StringVal("ahoy"),
			cty.StringVal("ahoy"),
			``,
		},
		{
			"constrained_string_required",
			cty.UnknownVal(cty.String),
			cty.UnknownVal(cty.String),
			``,
		},

		// constrained_string_optional_default_string
		{
			"constrained_string_optional_default_string",
			cty.NilVal,
			cty.StringVal("hello"), // the declared default value
			``,
		},
		{
			"constrained_string_optional_default_string",
			cty.NullVal(cty.DynamicPseudoType),
			cty.StringVal("hello"), // the declared default value
			``,
		},
		{
			"constrained_string_optional_default_string",
			cty.StringVal("ahoy"),
			cty.StringVal("ahoy"),
			``,
		},
		{
			"constrained_string_optional_default_string",
			cty.UnknownVal(cty.String),
			cty.UnknownVal(cty.String),
			``,
		},

		// constrained_string_optional_default_bool
		{
			"constrained_string_optional_default_bool",
			cty.NilVal,
			cty.StringVal("true"), // the declared default value, automatically converted to match type constraint
			``,
		},
		{
			"constrained_string_optional_default_bool",
			cty.NullVal(cty.DynamicPseudoType),
			cty.StringVal("true"), // the declared default value, automatically converted to match type constraint
			``,
		},
		{
			"constrained_string_optional_default_bool",
			cty.StringVal("ahoy"),
			cty.StringVal("ahoy"),
			``,
		},
		{
			"constrained_string_optional_default_bool",
			cty.UnknownVal(cty.String),
			cty.UnknownVal(cty.String),
			``,
		},

		// sensitive
		{
			"constrained_string_sensitive_required",
			cty.UnknownVal(cty.String),
			cty.UnknownVal(cty.String),
			``,
		},
	}

	for _, test := range tests {
		t.Run(fmt.Sprintf("%s %#v", test.varName, test.given), func(t *testing.T) {
			varAddr := addrs.InputVariable{Name: test.varName}.Absolute(addrs.RootModuleInstance)
			varCfg := variableConfigs[test.varName]
			if varCfg == nil {
				t.Fatalf("invalid variable name %q", test.varName)
			}

			t.Logf(
				"test case\nvariable:    %s\nconstraint:  %#v\ndefault:     %#v\nnullable:    %#v\ngiven value: %#v",
				varAddr,
				varCfg.Type,
				varCfg.Default,
				varCfg.Nullable,
				test.given,
			)

			rawVal := &InputValue{
				Value:      test.given,
				SourceType: ValueFromCaller,
			}

			got, diags := prepareFinalInputVariableValue(
				varAddr, rawVal, varCfg,
			)

			if test.wantErr != "" {
				if !diags.HasErrors() {
					t.Errorf("unexpected success\nwant error: %s", test.wantErr)
				} else if got, want := diags.Err().Error(), test.wantErr; got != want {
					t.Errorf("wrong error\ngot:  %s\nwant: %s", got, want)
				}
			} else {
				if diags.HasErrors() {
					t.Errorf("unexpected error\ngot: %s", diags.Err().Error())
				}
			}

			// NOTE: should still have returned some reasonable value even if there was an error
			if !test.want.RawEquals(got) {
				t.Fatalf("wrong result\ngot:  %#v\nwant: %#v", got, test.want)
			}
		})
	}

	t.Run("SourceType error message variants", func(t *testing.T) {
		tests := []struct {
			SourceType  ValueSourceType
			SourceRange tfdiags.SourceRange
			WantTypeErr string
			WantNullErr string
		}{
			{
				ValueFromUnknown,
				tfdiags.SourceRange{},
				`Invalid value for input variable: Unsuitable value for var.constrained_string_required set from outside of the configuration: string required.`,
				`Required variable not set: Unsuitable value for var.constrained_string_required set from outside of the configuration: required variable may not be set to null.`,
			},
			{
				ValueFromConfig,
				tfdiags.SourceRange{
					Filename: "example.tf",
					Start:    tfdiags.SourcePos(hcl.InitialPos),
					End:      tfdiags.SourcePos(hcl.InitialPos),
				},
				`Invalid value for input variable: The given value is not suitable for var.constrained_string_required declared at main.tf:32,3-41: string required.`,
				`Required variable not set: The given value is not suitable for var.constrained_string_required defined at main.tf:32,3-41: required variable may not be set to null.`,
			},
			{
				ValueFromAutoFile,
				tfdiags.SourceRange{
					Filename: "example.auto.tfvars",
					Start:    tfdiags.SourcePos(hcl.InitialPos),
					End:      tfdiags.SourcePos(hcl.InitialPos),
				},
				`Invalid value for input variable: The given value is not suitable for var.constrained_string_required declared at main.tf:32,3-41: string required.`,
				`Required variable not set: The given value is not suitable for var.constrained_string_required defined at main.tf:32,3-41: required variable may not be set to null.`,
			},
			{
				ValueFromNamedFile,
				tfdiags.SourceRange{
					Filename: "example.tfvars",
					Start:    tfdiags.SourcePos(hcl.InitialPos),
					End:      tfdiags.SourcePos(hcl.InitialPos),
				},
				`Invalid value for input variable: The given value is not suitable for var.constrained_string_required declared at main.tf:32,3-41: string required.`,
				`Required variable not set: The given value is not suitable for var.constrained_string_required defined at main.tf:32,3-41: required variable may not be set to null.`,
			},
			{
				ValueFromCLIArg,
				tfdiags.SourceRange{},
				`Invalid value for input variable: Unsuitable value for var.constrained_string_required set using -var="constrained_string_required=...": string required.`,
				`Required variable not set: Unsuitable value for var.constrained_string_required set using -var="constrained_string_required=...": required variable may not be set to null.`,
			},
			{
				ValueFromEnvVar,
				tfdiags.SourceRange{},
				`Invalid value for input variable: Unsuitable value for var.constrained_string_required set using the TF_VAR_constrained_string_required environment variable: string required.`,
				`Required variable not set: Unsuitable value for var.constrained_string_required set using the TF_VAR_constrained_string_required environment variable: required variable may not be set to null.`,
			},
			{
				ValueFromInput,
				tfdiags.SourceRange{},
				`Invalid value for input variable: Unsuitable value for var.constrained_string_required set using an interactive prompt: string required.`,
				`Required variable not set: Unsuitable value for var.constrained_string_required set using an interactive prompt: required variable may not be set to null.`,
			},
			{
				// NOTE: This isn't actually a realistic case for this particular
				// function, because if we have a value coming from a plan then
				// we must be in the apply step, and we shouldn't be able to
				// get past the plan step if we have invalid variable values,
				// and during planning we'll always have other source types.
				ValueFromPlan,
				tfdiags.SourceRange{},
				`Invalid value for input variable: Unsuitable value for var.constrained_string_required set from outside of the configuration: string required.`,
				`Required variable not set: Unsuitable value for var.constrained_string_required set from outside of the configuration: required variable may not be set to null.`,
			},
			{
				ValueFromCaller,
				tfdiags.SourceRange{},
				`Invalid value for input variable: Unsuitable value for var.constrained_string_required set from outside of the configuration: string required.`,
				`Required variable not set: Unsuitable value for var.constrained_string_required set from outside of the configuration: required variable may not be set to null.`,
			},
		}

		for _, test := range tests {
			t.Run(fmt.Sprintf("%s %s", test.SourceType, test.SourceRange.StartString()), func(t *testing.T) {
				varAddr := addrs.InputVariable{Name: "constrained_string_required"}.Absolute(addrs.RootModuleInstance)
				varCfg := variableConfigs[varAddr.Variable.Name]
				t.Run("type error", func(t *testing.T) {
					rawVal := &InputValue{
						Value:       cty.EmptyObjectVal,
						SourceType:  test.SourceType,
						SourceRange: test.SourceRange,
					}

					_, diags := prepareFinalInputVariableValue(
						varAddr, rawVal, varCfg,
					)
					if !diags.HasErrors() {
						t.Fatalf("unexpected success; want error")
					}

					if got, want := diags.Err().Error(), test.WantTypeErr; got != want {
						t.Errorf("wrong error\ngot:  %s\nwant: %s", got, want)
					}
				})
				t.Run("null error", func(t *testing.T) {
					rawVal := &InputValue{
						Value:       cty.NullVal(cty.DynamicPseudoType),
						SourceType:  test.SourceType,
						SourceRange: test.SourceRange,
					}

					_, diags := prepareFinalInputVariableValue(
						varAddr, rawVal, varCfg,
					)
					if !diags.HasErrors() {
						t.Fatalf("unexpected success; want error")
					}

					if got, want := diags.Err().Error(), test.WantNullErr; got != want {
						t.Errorf("wrong error\ngot:  %s\nwant: %s", got, want)
					}
				})
			})
		}
	})

	t.Run("SensitiveVariable error message variants, with source variants", func(t *testing.T) {
		tests := []struct {
			SourceType  ValueSourceType
			SourceRange tfdiags.SourceRange
			WantTypeErr string
			HideSubject bool
		}{
			{
				ValueFromUnknown,
				tfdiags.SourceRange{},
				"Invalid value for input variable: Unsuitable value for var.constrained_string_sensitive_required set from outside of the configuration: string required.",
				false,
			},
			{
				ValueFromConfig,
				tfdiags.SourceRange{
					Filename: "example.tfvars",
					Start:    tfdiags.SourcePos(hcl.InitialPos),
					End:      tfdiags.SourcePos(hcl.InitialPos),
				},
				`Invalid value for input variable: The given value is not suitable for var.constrained_string_sensitive_required, which is sensitive: string required. Invalid value defined at example.tfvars:1,1-1.`,
				true,
			},
		}

		for _, test := range tests {
			t.Run(fmt.Sprintf("%s %s", test.SourceType, test.SourceRange.StartString()), func(t *testing.T) {
				varAddr := addrs.InputVariable{Name: "constrained_string_sensitive_required"}.Absolute(addrs.RootModuleInstance)
				varCfg := variableConfigs[varAddr.Variable.Name]
				t.Run("type error", func(t *testing.T) {
					rawVal := &InputValue{
						Value:       cty.EmptyObjectVal,
						SourceType:  test.SourceType,
						SourceRange: test.SourceRange,
					}

					_, diags := prepareFinalInputVariableValue(
						varAddr, rawVal, varCfg,
					)
					if !diags.HasErrors() {
						t.Fatalf("unexpected success; want error")
					}

					if got, want := diags.Err().Error(), test.WantTypeErr; got != want {
						t.Errorf("wrong error\ngot:  %s\nwant: %s", got, want)
					}

					if test.HideSubject {
						if got, want := diags[0].Source().Subject.StartString(), test.SourceRange.StartString(); got == want {
							t.Errorf("Subject start should have been hidden, but was %s", got)
						}
					}
				})
			})
		}
	})
}

// These tests cover the JSON syntax configuration edge case handling,
// the background of which is described in detail in comments in the
// evalVariableValidations function. Future versions of Terraform may
// be able to remove this behaviour altogether.
func TestEvalVariableValidations_jsonErrorMessageEdgeCase(t *testing.T) {
	cfgSrc := `{
  "variable": {
    "valid": {
      "type": "string",
      "validation": {
        "condition": "${var.valid != \"bar\"}",
        "error_message": "Valid template string ${var.valid}"
      }
    },
    "invalid": {
      "type": "string",
      "validation": {
        "condition": "${var.invalid != \"bar\"}",
        "error_message": "Invalid template string ${"
      }
    }
  }
}
`
	cfg := testModuleInline(t, map[string]string{
		"main.tf.json": cfgSrc,
	})
	variableConfigs := cfg.Module.Variables

	// Because we loaded our pseudo-module from a temporary file, the
	// declaration source ranges will have unpredictable filenames. We'll
	// fix that here just to make things easier below.
	for _, vc := range variableConfigs {
		vc.DeclRange.Filename = "main.tf.json"
		for _, v := range vc.Validations {
			v.DeclRange.Filename = "main.tf.json"
		}
	}

	tests := []struct {
		varName  string
		given    cty.Value
		wantErr  []string
		wantWarn []string
	}{
		// Valid variable validation declaration, assigned value which passes
		// the condition generates no diagnostics.
		{
			varName: "valid",
			given:   cty.StringVal("foo"),
		},
		// Assigning a value which fails the condition generates an error
		// message with the expression successfully evaluated.
		{
			varName: "valid",
			given:   cty.StringVal("bar"),
			wantErr: []string{
				"Invalid value for variable",
				"Valid template string bar",
			},
		},
		// Invalid variable validation declaration due to an unparseable
		// template string. Assigning a value which passes the condition
		// results in a warning about the error message.
		{
			varName: "invalid",
			given:   cty.StringVal("foo"),
			wantWarn: []string{
				"Validation error message expression is invalid",
				"Missing expression; Expected the start of an expression, but found the end of the file.",
			},
		},
		// Assigning a value which fails the condition generates an error
		// message including the configured string interpreted as a literal
		// value, and the same warning diagnostic as above.
		{
			varName: "invalid",
			given:   cty.StringVal("bar"),
			wantErr: []string{
				"Invalid value for variable",
				"Invalid template string ${",
			},
			wantWarn: []string{
				"Validation error message expression is invalid",
				"Missing expression; Expected the start of an expression, but found the end of the file.",
			},
		},
	}

	for _, test := range tests {
		t.Run(fmt.Sprintf("%s %#v", test.varName, test.given), func(t *testing.T) {
			varAddr := addrs.InputVariable{Name: test.varName}.Absolute(addrs.RootModuleInstance)
			varCfg := variableConfigs[test.varName]
			if varCfg == nil {
				t.Fatalf("invalid variable name %q", test.varName)
			}

			// Build a mock context to allow the function under test to
			// retrieve the variable value and evaluate the expressions
			ctx := &MockEvalContext{}

			// We need a minimal scope to allow basic functions to be passed to
			// the HCL scope
			ctx.EvaluationScopeScope = &lang.Scope{}
			ctx.GetVariableValueFunc = func(addr addrs.AbsInputVariableInstance) cty.Value {
				if got, want := addr.String(), varAddr.String(); got != want {
					t.Errorf("incorrect argument to GetVariableValue: got %s, want %s", got, want)
				}
				return test.given
			}

			gotDiags := evalVariableValidations(
				varAddr, varCfg, nil, ctx,
			)

			if len(test.wantErr) == 0 && len(test.wantWarn) == 0 {
				if len(gotDiags) > 0 {
					t.Errorf("no diags expected, got %s", gotDiags.Err().Error())
				}
			} else {
			wantErrs:
				for _, want := range test.wantErr {
					for _, diag := range gotDiags {
						if diag.Severity() != tfdiags.Error {
							continue
						}
						desc := diag.Description()
						if strings.Contains(desc.Summary, want) || strings.Contains(desc.Detail, want) {
							continue wantErrs
						}
					}
					t.Errorf("no error diagnostics found containing %q\ngot: %s", want, gotDiags.Err().Error())
				}

			wantWarns:
				for _, want := range test.wantWarn {
					for _, diag := range gotDiags {
						if diag.Severity() != tfdiags.Warning {
							continue
						}
						desc := diag.Description()
						if strings.Contains(desc.Summary, want) || strings.Contains(desc.Detail, want) {
							continue wantWarns
						}
					}
					t.Errorf("no warning diagnostics found containing %q\ngot: %s", want, gotDiags.Err().Error())
				}
			}
		})
	}
}

func TestEvalVariableValidations_sensitiveValues(t *testing.T) {
	cfgSrc := `
variable "foo" {
  type      = string
  sensitive = true
  default   = "boop"

  validation {
    condition     = length(var.foo) == 4
	error_message = "Foo must be 4 characters, not ${length(var.foo)}"
  }
}

variable "bar" {
  type      = string
  sensitive = true
  default   = "boop"

  validation {
    condition     = length(var.bar) == 4
	error_message = "Bar must be 4 characters, not ${nonsensitive(length(var.bar))}."
  }
}
`
	cfg := testModuleInline(t, map[string]string{
		"main.tf": cfgSrc,
	})
	variableConfigs := cfg.Module.Variables

	// Because we loaded our pseudo-module from a temporary file, the
	// declaration source ranges will have unpredictable filenames. We'll
	// fix that here just to make things easier below.
	for _, vc := range variableConfigs {
		vc.DeclRange.Filename = "main.tf"
		for _, v := range vc.Validations {
			v.DeclRange.Filename = "main.tf"
		}
	}

	tests := []struct {
		varName string
		given   cty.Value
		wantErr []string
	}{
		// Validations pass on a sensitive variable with an error message which
		// would generate a sensitive value
		{
			varName: "foo",
			given:   cty.StringVal("boop"),
		},
		// Assigning a value which fails the condition generates a sensitive
		// error message, which is elided and generates another error
		{
			varName: "foo",
			given:   cty.StringVal("bap"),
			wantErr: []string{
				"Invalid value for variable",
				"The error message included a sensitive value, so it will not be displayed.",
				"Error message refers to sensitive values",
			},
		},
		// Validations pass on a sensitive variable with a correctly defined
		// error message
		{
			varName: "bar",
			given:   cty.StringVal("boop"),
		},
		// Assigning a value which fails the condition generates a nonsensitive
		// error message, which is displayed
		{
			varName: "bar",
			given:   cty.StringVal("bap"),
			wantErr: []string{
				"Invalid value for variable",
				"Bar must be 4 characters, not 3.",
			},
		},
	}

	for _, test := range tests {
		t.Run(fmt.Sprintf("%s %#v", test.varName, test.given), func(t *testing.T) {
			varAddr := addrs.InputVariable{Name: test.varName}.Absolute(addrs.RootModuleInstance)
			varCfg := variableConfigs[test.varName]
			if varCfg == nil {
				t.Fatalf("invalid variable name %q", test.varName)
			}

			// Build a mock context to allow the function under test to
			// retrieve the variable value and evaluate the expressions
			ctx := &MockEvalContext{}

			// We need a minimal scope to allow basic functions to be passed to
			// the HCL scope
			ctx.EvaluationScopeScope = &lang.Scope{}
			ctx.GetVariableValueFunc = func(addr addrs.AbsInputVariableInstance) cty.Value {
				if got, want := addr.String(), varAddr.String(); got != want {
					t.Errorf("incorrect argument to GetVariableValue: got %s, want %s", got, want)
				}
				if varCfg.Sensitive {
					return test.given.Mark(marks.Sensitive)
				} else {
					return test.given
				}
			}

			gotDiags := evalVariableValidations(
				varAddr, varCfg, nil, ctx,
			)

			if len(test.wantErr) == 0 {
				if len(gotDiags) > 0 {
					t.Errorf("no diags expected, got %s", gotDiags.Err().Error())
				}
			} else {
			wantErrs:
				for _, want := range test.wantErr {
					for _, diag := range gotDiags {
						if diag.Severity() != tfdiags.Error {
							continue
						}
						desc := diag.Description()
						if strings.Contains(desc.Summary, want) || strings.Contains(desc.Detail, want) {
							continue wantErrs
						}
					}
					t.Errorf("no error diagnostics found containing %q\ngot: %s", want, gotDiags.Err().Error())
				}
			}
		})
	}
}