bake: add unixtimestampparse function

Signed-off-by: CrazyMax <[email protected]>

Author: crazy-max

bake/hclparser/stdlib.go

@@ -127,6 +127,7 @@ var stdlibFunctions = []funcDef{
 	{name: "trimspace", fn: stdlib.TrimSpaceFunc},
 	{name: "trimsuffix", fn: stdlib.TrimSuffixFunc},
 	{name: "try", fn: tryfunc.TryFunc, descriptionAlt: `Variadic function that tries to evaluate all of is arguments in sequence until one succeeds, in which case it returns that result, or returns an error if none of them succeed.`},
+	{name: "unixtimestampparse", factory: unixtimestampParseFunc},
 	{name: "upper", fn: stdlib.UpperFunc},
 	{name: "urlencode", fn: encoding.URLEncodeFunc, descriptionAlt: `Applies URL encoding to a given string.`},
 	{name: "uuidv4", fn: uuid.V4Func, descriptionAlt: `Generates and returns a Type-4 UUID in the standard hexadecimal string format.`},
@@ -248,7 +249,7 @@ func sanitizeFunc() function.Function {
 
 // timestampFunc constructs a function that returns a string representation of the current date and time.
 //
-// This function was imported from terraform's datetime utilities.
+// This function was imported from Terraform's datetime utilities.
 func timestampFunc() function.Function {
 	return function.New(&function.Spec{
 		Description: `Returns a string representation of the current date and time.`,
@@ -281,6 +282,59 @@ func homedirFunc() function.Function {
 	})
 }
 
+// unixtimestampParseFunc, given a unix timestamp integer, will parse and
+// return an object representation of that date and time
+//
+// This function is similar to the `unix_timestamp_parse` function in Terraform:
+// https://registry.terraform.io/providers/hashicorp/time/latest/docs/functions/unix_timestamp_parse
+func unixtimestampParseFunc() function.Function {
+	return function.New(&function.Spec{
+		Description: `Given a unix timestamp integer, will parse and return an object representation of that date and time. A unix timestamp is the number of seconds elapsed since January 1, 1970 UTC.`,
+		Params: []function.Parameter{
+			{
+				Name:        "unix_timestamp",
+				Description: "Unix Timestamp integer to parse",
+				Type:        cty.Number,
+			},
+		},
+		Type: function.StaticReturnType(cty.Object(map[string]cty.Type{
+			"year":         cty.Number,
+			"year_day":     cty.Number,
+			"day":          cty.Number,
+			"month":        cty.Number,
+			"month_name":   cty.String,
+			"weekday":      cty.Number,
+			"weekday_name": cty.String,
+			"hour":         cty.Number,
+			"minute":       cty.Number,
+			"second":       cty.Number,
+			"rfc3339":      cty.String,
+			"iso_year":     cty.Number,
+			"iso_week":     cty.Number,
+		})),
+		Impl: func(args []cty.Value, retType cty.Type) (cty.Value, error) {
+			ts, _ := args[0].AsBigFloat().Int64()
+			unixTime := time.Unix(ts, 0).UTC()
+			isoYear, isoWeek := unixTime.ISOWeek()
+			return cty.ObjectVal(map[string]cty.Value{
+				"year":         cty.NumberIntVal(int64(unixTime.Year())),
+				"year_day":     cty.NumberIntVal(int64(unixTime.YearDay())),
+				"day":          cty.NumberIntVal(int64(unixTime.Day())),
+				"month":        cty.NumberIntVal(int64(unixTime.Month())),
+				"month_name":   cty.StringVal(unixTime.Month().String()),
+				"weekday":      cty.NumberIntVal(int64(unixTime.Weekday())),
+				"weekday_name": cty.StringVal(unixTime.Weekday().String()),
+				"hour":         cty.NumberIntVal(int64(unixTime.Hour())),
+				"minute":       cty.NumberIntVal(int64(unixTime.Minute())),
+				"second":       cty.NumberIntVal(int64(unixTime.Second())),
+				"rfc3339":      cty.StringVal(unixTime.Format(time.RFC3339)),
+				"iso_year":     cty.NumberIntVal(int64(isoYear)),
+				"iso_week":     cty.NumberIntVal(int64(isoWeek)),
+			}), nil
+		},
+	})
+}
+
 func Stdlib() map[string]function.Function {
 	funcs := make(map[string]function.Function, len(stdlibFunctions))
 	for _, v := range stdlibFunctions {

bake/hclparser/stdlib_test.go

@@ -205,3 +205,29 @@ func TestHomedir(t *testing.T) {
 	require.NotEmpty(t, home.AsString())
 	require.True(t, filepath.IsAbs(home.AsString()))
 }
+
+func TestUnixTimestampParseFunc(t *testing.T) {
+	fn := unixtimestampParseFunc()
+	input := cty.NumberIntVal(1690328596)
+	got, err := fn.Call([]cty.Value{input})
+	require.NoError(t, err)
+
+	expected := map[string]cty.Value{
+		"year":         cty.NumberIntVal(2023),
+		"year_day":     cty.NumberIntVal(206),
+		"day":          cty.NumberIntVal(25),
+		"month":        cty.NumberIntVal(7),
+		"month_name":   cty.StringVal("July"),
+		"weekday":      cty.NumberIntVal(2),
+		"weekday_name": cty.StringVal("Tuesday"),
+		"hour":         cty.NumberIntVal(23),
+		"minute":       cty.NumberIntVal(43),
+		"second":       cty.NumberIntVal(16),
+		"rfc3339":      cty.StringVal("2023-07-25T23:43:16Z"),
+		"iso_year":     cty.NumberIntVal(2023),
+		"iso_week":     cty.NumberIntVal(30),
+	}
+	for k, v := range expected {
+		require.True(t, got.GetAttr(k).RawEquals(v), "field %s: got %v, want %v", k, got.GetAttr(k), v)
+	}
+}