add round function support

CHANGELOG.md

@@ -1,6 +1,6 @@
 ### 1.5.0 (Next)
 - Do not coerce `number` type ID to `string` type ID (may cause superficial plan changes to existing states).
-- Add `exp` and `mod` functions.
+- Add `exp`, `mod`, and `round` functions.
 
 ### 1.4.1
 - Add `sorted` parameter to `list_index` function.

examples/data-sources/stdlib_round/data-source.tf

@@ -0,0 +1,17 @@
+# Return the rounding of of 1.2
+data "stdlib_round" "down" {
+  param = 1.2
+}
+# => 1
+
+# Return the rounding of 1.8
+data "stdlib_round" "up" {
+  param = 1.8
+}
+# => 2
+
+# Return the rounding of 1.5
+data "stdlib_round" "half" {
+  param = 1.5
+}
+# => 2

stdlib/number/round_data_source_test.go

@@ -0,0 +1,54 @@
+package numberfunc_test
+
+import (
+	"testing"
+
+	"github.com/hashicorp/terraform-plugin-testing/helper/resource"
+
+	"github.com/mschuchard/terraform-provider-stdlib/stdlib"
+)
+
+func TestAccRound(test *testing.T) {
+	// invoke test
+	resource.ParallelTest(test, resource.TestCase{
+		ProtoV6ProviderFactories: provider.TestAccProtoV6ProviderFactories,
+		Steps: []resource.TestStep{
+			// test 1.2 round down
+			{
+				Config: `data "stdlib_round" "test" { param = 1.2 }`,
+				Check: resource.ComposeAggregateTestCheckFunc(
+					// verify input param is stored correctly
+					resource.TestCheckResourceAttr("data.stdlib_round.test", "param", "1.2"),
+					// verify rounding result is stored correctly
+					resource.TestCheckResourceAttr("data.stdlib_round.test", "result", "1"),
+					// verify id stored correctly
+					resource.TestCheckResourceAttr("data.stdlib_round.test", "id", "1.2"),
+				),
+			},
+			// test 1.8 round up
+			{
+				Config: `data "stdlib_round" "test" { param = 1.8 }`,
+				Check: resource.ComposeAggregateTestCheckFunc(
+					// verify input param is stored correctly
+					resource.TestCheckResourceAttr("data.stdlib_round.test", "param", "1.8"),
+					// verify rounding result is stored correctly
+					resource.TestCheckResourceAttr("data.stdlib_round.test", "result", "2"),
+					// verify id stored correctly
+					resource.TestCheckResourceAttr("data.stdlib_round.test", "id", "1.8"),
+				),
+			},
+			// test 1.5 round up
+			{
+				Config: `data "stdlib_round" "test" { param = 1.5 }`,
+				Check: resource.ComposeAggregateTestCheckFunc(
+					// verify input param is stored correctly
+					resource.TestCheckResourceAttr("data.stdlib_round.test", "param", "1.5"),
+					// verify rounding result is stored correctly
+					resource.TestCheckResourceAttr("data.stdlib_round.test", "result", "2"),
+					// verify id stored correctly
+					resource.TestCheckResourceAttr("data.stdlib_round.test", "id", "1.5"),
+				),
+			},
+		},
+	})
+}

stdlib/provider.go

@@ -66,6 +66,7 @@ func (_ *stdlibProvider) DataSources(_ context.Context) []func() datasource.Data
 		multiple.NewEmptyDataSource,
 		numberfunc.NewExpDataSource,
 		numberfunc.NewModDataSource,
+		numberfunc.NewRoundDataSource,
 		slicefunc.NewCompareListDataSource,
 		slicefunc.NewInsertDataSource,
 		slicefunc.NewLastElementDataSource,