feat: add negative and positive functions

docs/functions/negative.md

@@ -0,0 +1,39 @@
+---
+page_title: "negative function - terraform-provider-assert"
+subcategory: "Numeric Functions"
+description: |-
+  Checks whether a number is negative
+---
+
+# function: negative
+
+
+
+## Variable Validation Example
+
+```terraform
+variable "example" {
+  type = number
+  validation {
+    condition     = provider::assert::negative(var.example)
+    error_message = "Expected ${var.example} to be negative"
+  }
+}
+```
+
+## Signature
+
+<!-- signature generated by tfplugindocs -->
+```text
+negative(number number) bool
+```
+
+## Arguments
+
+<!-- arguments generated by tfplugindocs -->
+1. `number` (Number) The number to check
+
+
+## Return Type
+
+The return type of `negative` is a boolean.

docs/functions/positive.md

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+---
+page_title: "positive function - terraform-provider-assert"
+subcategory: "Numeric Functions"
+description: |-
+  Checks whether a number is positive
+---
+
+# function: positive
+
+
+
+## Variable Validation Example
+
+```terraform
+variable "example" {
+  type = number
+  validation {
+    condition     = provider::assert::positive(var.example)
+    error_message = "Expected ${var.example} to be positive"
+  }
+}
+```
+
+## Signature
+
+<!-- signature generated by tfplugindocs -->
+```text
+positive(number number) bool
+```
+
+## Arguments
+
+<!-- arguments generated by tfplugindocs -->
+1. `number` (Number) The number to check
+
+
+## Return Type
+
+The return type of `positive` is a boolean.

examples/functions/negative/variable.tf

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+variable "example" {
+  type = number
+  validation {
+    condition     = provider::assert::negative(var.example)
+    error_message = "Expected ${var.example} to be negative"
+  }
+}

examples/functions/positive/variable.tf

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+variable "example" {
+  type = number
+  validation {
+    condition     = provider::assert::positive(var.example)
+    error_message = "Expected ${var.example} to be positive"
+  }
+}

internal/provider/negative_function.go

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+// Copyright (c) HashiCorp, Inc.
+// SPDX-License-Identifier: MPL-2.0
+
+package provider
+
+import (
+	"context"
+	"math/big"
+
+	"github.com/hashicorp/terraform-plugin-framework/function"
+)
+
+var (
+	_ function.Function = NegativeFunction{}
+)
+
+func NewNegativeFunction() function.Function {
+	return NegativeFunction{}
+}
+
+type NegativeFunction struct{}
+
+func (r NegativeFunction) Metadata(_ context.Context, req function.MetadataRequest, resp *function.MetadataResponse) {
+	resp.Name = "negative"
+}
+
+func (r NegativeFunction) Definition(_ context.Context, _ function.DefinitionRequest, resp *function.DefinitionResponse) {
+	resp.Definition = function.Definition{
+		Summary: "Checks whether a number is negative",
+		Parameters: []function.Parameter{
+			function.NumberParameter{
+				AllowNullValue:     false,
+				AllowUnknownValues: true,
+				Description:        "The number to check",
+				Name:               "number",
+			},
+		},
+		Return: function.BoolReturn{},
+	}
+}
+
+func (r NegativeFunction) Run(ctx context.Context, req function.RunRequest, resp *function.RunResponse) {
+	var number *big.Float
+
+	resp.Error = function.ConcatFuncErrors(req.Arguments.Get(ctx, &number))
+	if resp.Error != nil {
+		return
+	}
+	resp.Error = function.ConcatFuncErrors(resp.Result.Set(ctx, number.Cmp(big.NewFloat(0)) == -1))
+}

internal/provider/negative_function_test.go

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+// Copyright (c) HashiCorp, Inc.
+// SPDX-License-Identifier: MPL-2.0
+
+package provider
+
+import (
+	"testing"
+
+	"github.com/hashicorp/go-version"
+	"github.com/hashicorp/terraform-plugin-testing/helper/resource"
+	"github.com/hashicorp/terraform-plugin-testing/tfversion"
+)
+
+func TestNegativeFunction(t *testing.T) {
+	t.Parallel()
+	resource.UnitTest(t, resource.TestCase{
+		TerraformVersionChecks: []tfversion.TerraformVersionCheck{
+			tfversion.SkipBelow(version.Must(version.NewVersion(MinimalRequiredTerraformVersion))),
+		},
+		ProtoV6ProviderFactories: testAccProtoV6ProviderFactories,
+		Steps: []resource.TestStep{
+			{
+				Config: `
+output "test" {
+  value = provider::assert::negative(-5)
+}
+				`,
+				Check: resource.ComposeAggregateTestCheckFunc(
+					resource.TestCheckOutput("test", "true"),
+				),
+			},
+		},
+	})
+}
+
+func TestNegativeFunction_float(t *testing.T) {
+	t.Parallel()
+	resource.UnitTest(t, resource.TestCase{
+		TerraformVersionChecks: []tfversion.TerraformVersionCheck{
+			tfversion.SkipBelow(version.Must(version.NewVersion(MinimalRequiredTerraformVersion))),
+		},
+		ProtoV6ProviderFactories: testAccProtoV6ProviderFactories,
+		Steps: []resource.TestStep{
+			{
+				Config: `
+output "test" {
+  value = provider::assert::negative(-50.32132)
+}
+				`,
+				Check: resource.ComposeAggregateTestCheckFunc(
+					resource.TestCheckOutput("test", "true"),
+				),
+			},
+		},
+	})
+}
+
+func TestNegativeFunction_falseCases(t *testing.T) {
+	t.Parallel()
+	resource.UnitTest(t, resource.TestCase{
+		TerraformVersionChecks: []tfversion.TerraformVersionCheck{
+			tfversion.SkipBelow(version.Must(version.NewVersion(MinimalRequiredTerraformVersion))),
+		},
+		ProtoV6ProviderFactories: testAccProtoV6ProviderFactories,
+		Steps: []resource.TestStep{
+			{
+				Config: `
+output "test" {
+  value = provider::assert::negative(0)
+}
+				`,
+				Check: resource.ComposeAggregateTestCheckFunc(
+					resource.TestCheckOutput("test", "false"),
+				),
+			},
+			{
+				Config: `
+output "test" {
+  value = provider::assert::negative(0.0)
+}
+				`,
+				Check: resource.ComposeAggregateTestCheckFunc(
+					resource.TestCheckOutput("test", "false"),
+				),
+			},
+			{
+				Config: `
+output "test" {
+  value = provider::assert::negative(1)
+}
+				`,
+				Check: resource.ComposeAggregateTestCheckFunc(
+					resource.TestCheckOutput("test", "false"),
+				),
+			},
+			{
+				Config: `
+output "test" {
+  value = provider::assert::negative(5)
+}
+				`,
+				Check: resource.ComposeAggregateTestCheckFunc(
+					resource.TestCheckOutput("test", "false"),
+				),
+			},
+			{
+				Config: `
+output "test" {
+  value = provider::assert::negative(50.32132)
+}
+				`,
+				Check: resource.ComposeAggregateTestCheckFunc(
+					resource.TestCheckOutput("test", "false"),
+				),
+			},
+		},
+	})
+}

internal/provider/positive_function.go

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+// Copyright (c) HashiCorp, Inc.
+// SPDX-License-Identifier: MPL-2.0
+
+package provider
+
+import (
+	"context"
+	"math/big"
+
+	"github.com/hashicorp/terraform-plugin-framework/function"
+)
+
+var (
+	_ function.Function = PositiveFunction{}
+)
+
+func NewPositiveFunction() function.Function {
+	return PositiveFunction{}
+}
+
+type PositiveFunction struct{}
+
+func (r PositiveFunction) Metadata(_ context.Context, req function.MetadataRequest, resp *function.MetadataResponse) {
+	resp.Name = "positive"
+}
+
+func (r PositiveFunction) Definition(_ context.Context, _ function.DefinitionRequest, resp *function.DefinitionResponse) {
+	resp.Definition = function.Definition{
+		Summary: "Checks whether a number is positive",
+		Parameters: []function.Parameter{
+			function.NumberParameter{
+				AllowNullValue:     false,
+				AllowUnknownValues: true,
+				Description:        "The number to check",
+				Name:               "number",
+			},
+		},
+		Return: function.BoolReturn{},
+	}
+}
+
+func (r PositiveFunction) Run(ctx context.Context, req function.RunRequest, resp *function.RunResponse) {
+	var number *big.Float
+
+	resp.Error = function.ConcatFuncErrors(req.Arguments.Get(ctx, &number))
+	if resp.Error != nil {
+		return
+	}
+	resp.Error = function.ConcatFuncErrors(resp.Result.Set(ctx, number.Cmp(big.NewFloat(0)) == 1))
+}