bake: add unixtimestampparse function

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

Author: crazy-max

bake/hclparser/stdlib.go

@@ -122,6 +122,7 @@ 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.`},
@@ -311,6 +312,59 @@ func rfc3339ParseFunc() 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

@@ -226,3 +226,29 @@ func TestRfc3339ParseFunc(t *testing.T) {
 	_, err = fn.Call([]cty.Value{cty.StringVal("not-a-date")})
 	require.Error(t, err)
 }
+
+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)
+	}
+}

docs/bake-stdlib.md

@@ -103,6 +103,7 @@ title: Bake standard library functions
 | `trimspace`              | Removes any consecutive space characters (as defined by Unicode) from the start and end of the given string.                                                                                                 |
 | `trimsuffix`             | Removes the given suffix from the start of the given string, if present.                                                                                                                                     |
 | `try`                    | 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.                              |
+| `unixtimestampparse`     | 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.                           |
 | `upper`                  | Returns the given string with all Unicode letters translated to their uppercase equivalents.                                                                                                                 |
 | `urlencode`              | Applies URL encoding to a given string.                                                                                                                                                                      |
 | `uuidv4`                 | Generates and returns a Type-4 UUID in the standard hexadecimal string format.                                                                                                                               |