Support for CUE (#1781)

Signed-off-by: Dave Henderson <dhenderson@gmail.com>

9 files changed, 287 insertions, 1 deletions

diff --git a/data/data.go b/data/data.go
index adf6b2b7..d2fc32fb 100644
--- a/data/data.go
+++ b/data/data.go
@@ -12,6 +12,9 @@ import (
 	"io"
 	"strings"
 
+	"cuelang.org/go/cue"
+	"cuelang.org/go/cue/cuecontext"
+	"cuelang.org/go/cue/format"
 	"github.com/Shopify/ejson"
 	ejsonJson "github.com/Shopify/ejson/json"
 	"github.com/hairyhenderson/gomplate/v4/conv"
@@ -442,3 +445,63 @@ func ToTOML(in interface{}) (string, error) {
 	}
 	return buf.String(), nil
 }
+
+// CUE - Unmarshal a CUE expression into the appropriate type
+func CUE(in string) (interface{}, error) {
+	cuectx := cuecontext.New()
+	val := cuectx.CompileString(in)
+
+	if val.Err() != nil {
+		return nil, fmt.Errorf("unable to process CUE: %w", val.Err())
+	}
+
+	switch val.Kind() {
+	case cue.StructKind:
+		out := map[string]interface{}{}
+		err := val.Decode(&out)
+		return out, err
+	case cue.ListKind:
+		out := []interface{}{}
+		err := val.Decode(&out)
+		return out, err
+	case cue.BytesKind:
+		out := []byte{}
+		err := val.Decode(&out)
+		return out, err
+	case cue.StringKind:
+		out := ""
+		err := val.Decode(&out)
+		return out, err
+	case cue.IntKind:
+		out := 0
+		err := val.Decode(&out)
+		return out, err
+	case cue.NumberKind, cue.FloatKind:
+		out := 0.0
+		err := val.Decode(&out)
+		return out, err
+	case cue.BoolKind:
+		out := false
+		err := val.Decode(&out)
+		return out, err
+	case cue.NullKind:
+		return nil, nil
+	default:
+		return nil, fmt.Errorf("unsupported CUE type %q", val.Kind())
+	}
+}
+
+func ToCUE(in interface{}) (string, error) {
+	cuectx := cuecontext.New()
+	v := cuectx.Encode(in)
+	if v.Err() != nil {
+		return "", v.Err()
+	}
+
+	bs, err := format.Node(v.Syntax())
+	if err != nil {
+		return "", err
+	}
+
+	return string(bs), nil
+}
diff --git a/data/data_test.go b/data/data_test.go
index 2ea6365e..324a3600 100644
--- a/data/data_test.go
+++ b/data/data_test.go
@@ -660,3 +660,120 @@ func TestStringifyYAMLMapMapKeys(t *testing.T) {
 		assert.EqualValues(t, c.want, c.input)
 	}
 }
+
+func TestCUE(t *testing.T) {
+	in := `package foo
+import "regexp"
+matches: regexp.FindSubmatch(#"^([^:]*):(\d+)$"#, "localhost:443")
+one: 1
+two: 2
+// A field using quotes.
+"two-and-a-half": 2.5
+list: [ 1, 2, 3 ]
+`
+
+	expected := map[string]interface{}{
+		"matches": []interface{}{
+			"localhost:443",
+			"localhost",
+			"443",
+		},
+		"one":            1,
+		"two":            2,
+		"two-and-a-half": 2.5,
+		"list":           []interface{}{1, 2, 3},
+	}
+
+	out, err := CUE(in)
+	require.NoError(t, err)
+	assert.EqualValues(t, expected, out)
+
+	out, err = CUE(`[1,2,3]`)
+	require.NoError(t, err)
+	assert.EqualValues(t, []interface{}{1, 2, 3}, out)
+
+	out, err = CUE(`"hello world"`)
+	require.NoError(t, err)
+	assert.EqualValues(t, "hello world", out)
+
+	out, err = CUE(`true`)
+	require.NoError(t, err)
+	assert.EqualValues(t, true, out)
+
+	out, err = CUE(`'\x00\x01\x02\x03\x04'`)
+	require.NoError(t, err)
+	assert.EqualValues(t, []byte{0, 1, 2, 3, 4}, out)
+
+	out, err = CUE(`42`)
+	require.NoError(t, err)
+	assert.EqualValues(t, 42, out)
+
+	out, err = CUE(`42.0`)
+	require.NoError(t, err)
+	assert.EqualValues(t, 42.0, out)
+
+	out, err = CUE(`null`)
+	require.NoError(t, err)
+	assert.EqualValues(t, nil, out)
+
+	_, err = CUE(`>=0 & <=7 & >=3 & <=10`)
+	require.Error(t, err)
+}
+
+func TestToCUE(t *testing.T) {
+	in := map[string]interface{}{
+		"matches": []interface{}{
+			"localhost:443",
+			"localhost",
+			"443",
+		},
+		"one":            1,
+		"two":            2,
+		"two-and-a-half": 2.5,
+		"list":           []interface{}{1, 2, 3},
+	}
+
+	expected := `{
+	"two-and-a-half": 2.5
+	list: [1, 2, 3]
+	two: 2
+	one: 1
+	matches: ["localhost:443", "localhost", "443"]
+}`
+
+	out, err := ToCUE(in)
+	require.NoError(t, err)
+	assert.EqualValues(t, expected, out)
+
+	out, err = ToCUE([]interface{}{1, 2, 3})
+	require.NoError(t, err)
+	assert.EqualValues(t, `[1, 2, 3]`, out)
+
+	out, err = ToCUE("hello world")
+	require.NoError(t, err)
+	assert.EqualValues(t, `"hello world"`, out)
+
+	out, err = ToCUE(true)
+	require.NoError(t, err)
+	assert.EqualValues(t, `true`, out)
+
+	out, err = ToCUE([]byte{0, 1, 2, 3, 4})
+	require.NoError(t, err)
+	assert.EqualValues(t, `'\x00\x01\x02\x03\x04'`, out)
+
+	out, err = ToCUE(42)
+	require.NoError(t, err)
+	assert.EqualValues(t, `42`, out)
+
+	out, err = ToCUE(42.0)
+	require.NoError(t, err)
+	assert.EqualValues(t, `42.0`, out)
+
+	out, err = ToCUE(nil)
+	require.NoError(t, err)
+	assert.EqualValues(t, `null`, out)
+
+	out, err = ToCUE(struct{}{})
+	require.NoError(t, err)
+	assert.EqualValues(t, `{}`, out)
+}
diff --git a/data/datasource.go b/data/datasource.go
index d16fe09a..fe3f0877 100644
--- a/data/datasource.go
+++ b/data/datasource.go
@@ -32,6 +32,7 @@ func init() {
 	regExtension(".csv", csvMimetype)
 	regExtension(".toml", tomlMimetype)
 	regExtension(".env", envMimetype)
+	regExtension(".cue", cueMimetype)
 }
 
 // registerReaders registers the source-reader functions
@@ -348,6 +349,8 @@ func parseData(mimeType, s string) (out interface{}, err error) {
 		out, err = dotEnv(s)
 	case textMimetype:
 		out = s
+	case cueMimetype:
+		out, err = CUE(s)
 	default:
 		return nil, fmt.Errorf("datasources of type %s not yet supported", mimeType)
 	}
diff --git a/data/mimetypes.go b/data/mimetypes.go
index bdc12ad4..1f243219 100644
--- a/data/mimetypes.go
+++ b/data/mimetypes.go
@@ -8,6 +8,7 @@ const (
 	tomlMimetype      = "application/toml"
 	yamlMimetype      = "application/yaml"
 	envMimetype       = "application/x-env"
+	cueMimetype       = "application/cue"
 )
 
 // mimeTypeAliases defines a mapping for non-canonical mime types that are
diff --git a/docs-src/content/functions/data.yml b/docs-src/content/functions/data.yml
index 9392790d..6753cafe 100644
--- a/docs-src/content/functions/data.yml
+++ b/docs-src/content/functions/data.yml
@@ -383,6 +383,27 @@ funcs:
         Go
         COBOL
         ```
+  - name: data.CUE
+    alias: cue
+    description: |
+      Converts a [CUE](https://cuelang.org/) document into an object. Any type
+      of CUE document is supported. This can be used to access properties of CUE
+      documents.
+
+      Note that the `import` statement is not yet supported, and will result in
+      an error (except for importing builtin packages).
+    pipeline: true
+    arguments:
+      - name: input
+        required: true
+        description: the CUE document to parse
+    examples:
+      - |
+        $ gomplate -i '{{ $t := `data: {
+            hello: "world"
+          }` -}}
+          Hello {{ (cue $t).data.hello }}'
+        Hello world
   - name: data.ToJSON
     alias: toJSON
     released: v2.0.0
@@ -511,3 +532,28 @@ funcs:
         1,2
         3,4
         ```
+  - name: data.ToCUE
+    alias: toCUE
+    description: |
+      Converts an object to a [CUE](https://cuelang.org/) document in canonical
+      format. The input object can be of any type.
+
+      This is roughly equivalent to using the `cue export --out=cue <file>`
+      command to convert from other formats to CUE.
+    pipeline: true
+    arguments:
+      - name: input
+        required: true
+        description: the object to marshal as a CUE document
+    examples:
+      - |
+        $ gomplate -i '{{ `{"foo":"bar"}` | data.JSON | data.ToCUE }}'
+        {
+        	foo: "bar"
+        }
+      - |
+        $ gomplate -i '{{ toCUE "hello world" }}'
+        "hello world"
+      - |
+        $ gomplate -i '{{ coll.Slice 1 "two" true | data.ToCUE }}'
+        [1, "two", true]
diff --git a/funcs/data.go b/funcs/data.go
index c706bc32..bb47988b 100644
--- a/funcs/data.go
+++ b/funcs/data.go
@@ -48,11 +48,13 @@ func CreateDataFuncs(ctx context.Context,
 	f["csv"] = ns.CSV
 	f["csvByRow"] = ns.CSVByRow
 	f["csvByColumn"] = ns.CSVByColumn
+	f["cue"] = ns.CUE
 	f["toJSON"] = ns.ToJSON
 	f["toJSONPretty"] = ns.ToJSONPretty
 	f["toYAML"] = ns.ToYAML
 	f["toTOML"] = ns.ToTOML
 	f["toCSV"] = ns.ToCSV
+	f["toCUE"] = ns.ToCUE
 	return f
 }
 
@@ -101,11 +103,21 @@ func (f *DataFuncs) CSVByColumn(args ...string) (cols map[string][]string, err e
 	return data.CSVByColumn(args...)
 }
 
+// CUE -
+func (f *DataFuncs) CUE(in interface{}) (interface{}, error) {
+	return data.CUE(conv.ToString(in))
+}
+
 // ToCSV -
 func (f *DataFuncs) ToCSV(args ...interface{}) (string, error) {
 	return data.ToCSV(args...)
 }
 
+// ToCUE -
+func (f *DataFuncs) ToCUE(in interface{}) (string, error) {
+	return data.ToCUE(in)
+}
+
 // ToJSON -
 func (f *DataFuncs) ToJSON(in interface{}) (string, error) {
 	return data.ToJSON(in)
diff --git a/go.mod b/go.mod
index c8140f5d..61c5d881 100644
--- a/go.mod
+++ b/go.mod
@@ -3,6 +3,7 @@ module github.com/hairyhenderson/gomplate/v4
 go 1.21
 
 require (
+	cuelang.org/go v0.6.0
 	github.com/Masterminds/goutils v1.1.1
 	github.com/Masterminds/semver/v3 v3.2.1
 	github.com/Shopify/ejson v1.4.1
@@ -74,6 +75,7 @@ require (
 	github.com/aws/smithy-go v1.13.5 // indirect
 	github.com/cenkalti/backoff/v3 v3.2.2 // indirect
 	github.com/cloudflare/circl v1.3.3 // indirect
+	github.com/cockroachdb/apd/v3 v3.2.0 // indirect
 	github.com/cyphar/filepath-securejoin v0.2.4 // indirect
 	github.com/davecgh/go-spew v1.1.2-0.20180830191138-d8f796af33cc // indirect
 	github.com/dustin/gojson v0.0.0-20160307161227-2e71ec9dd5ad // indirect
@@ -110,6 +112,7 @@ require (
 	github.com/mattn/go-isatty v0.0.19 // indirect
 	github.com/mitchellh/go-homedir v1.1.0 // indirect
 	github.com/mitchellh/mapstructure v1.5.0 // indirect
+	github.com/mpvl/unique v0.0.0-20150818121801-cbe035fff7de // indirect
 	github.com/pjbgf/sha1cd v0.3.0 // indirect
 	github.com/pmezard/go-difflib v1.0.1-0.20181226105442-5d4384ee4fb2 // indirect
 	github.com/ryanuber/go-glob v1.0.0 // indirect
diff --git a/go.sum b/go.sum
index 3cbe7e3c..306ccf2a 100644
--- a/go.sum
+++ b/go.sum
@@ -416,6 +416,8 @@ code.cloudfoundry.org/clock v0.0.0-20180518195852-02e53af36e6c/go.mod h1:QD9Lzhd
 contrib.go.opencensus.io/exporter/aws v0.0.0-20200617204711-c478e41e60e9/go.mod h1:uu1P0UCM/6RbsMrgPa98ll8ZcHM858i/AD06a9aLRCA=
 contrib.go.opencensus.io/exporter/stackdriver v0.13.14/go.mod h1:5pSSGY0Bhuk7waTHuDf4aQ8D2DrhgETRo9fy6k3Xlzc=
 contrib.go.opencensus.io/integrations/ocsql v0.1.7/go.mod h1:8DsSdjz3F+APR+0z0WkU1aRorQCFfRxvqjUUPMbF3fE=
+cuelang.org/go v0.6.0 h1:dJhgKCog+FEZt7OwAYV1R+o/RZPmE8aqFoptmxSWyr8=
+cuelang.org/go v0.6.0/go.mod h1:9CxOX8aawrr3BgSdqPj7V0RYoXo7XIb+yDFC6uESrOQ=
 dario.cat/mergo v1.0.0 h1:AGCNq9Evsj31mOgNPcLyXc+4PNABt905YmuqPYYpBWk=
 dario.cat/mergo v1.0.0/go.mod h1:uNxQE+84aUszobStD9th8a29P2fMDhsBdgRYvZOxGmk=
 dmitri.shuralyov.com/gpu/mtl v0.0.0-20190408044501-666a987793e9/go.mod h1:H6x//7gZCb22OMCxBHrMx7a5I7Hp++hsVxbQ4BYO7hU=
@@ -695,6 +697,8 @@ github.com/cncf/xds/go v0.0.0-20211011173535-cb28da3451f1/go.mod h1:eXthEFrGJvWH
 github.com/cncf/xds/go v0.0.0-20220314180256-7f1daf1720fc/go.mod h1:eXthEFrGJvWHgFFCl3hGmgk+/aYT6PnTQLykKQRLhEs=
 github.com/cncf/xds/go v0.0.0-20230105202645-06c439db220b/go.mod h1:eXthEFrGJvWHgFFCl3hGmgk+/aYT6PnTQLykKQRLhEs=
 github.com/cockroachdb/apd v1.1.0/go.mod h1:8Sl8LxpKi29FqWXR16WEFZRNSz3SoPzUzeMeY4+DwBQ=
+github.com/cockroachdb/apd/v3 v3.2.0 h1:79kHCn4tO0VGu3W0WujYrMjBDk8a2H4KEUYcXf7whcg=
+github.com/cockroachdb/apd/v3 v3.2.0/go.mod h1:klXJcjp+FffLTHlhIG69tezTDvdP065naDsHzKhYSqc=
 github.com/cockroachdb/datadriven v0.0.0-20190809214429-80d97fb3cbaa/go.mod h1:zn76sxSg3SzpJ0PPJaLDCu+Bu0Lg3sKTORVIj19EIF8=
 github.com/cockroachdb/datadriven v0.0.0-20200714090401-bf6692d28da5/go.mod h1:h6jFvWxBdQXxjopDMZyH2UVceIRfR84bdzbkoKrsWNo=
 github.com/cockroachdb/errors v1.2.4/go.mod h1:rQD95gz6FARkaKkQXUksEje/d9a6wBJoCr5oaCLELYA=
@@ -883,6 +887,8 @@ github.com/emicklei/go-restful v0.0.0-20170410110728-ff4f55a20633/go.mod h1:otzb
 github.com/emicklei/go-restful v2.9.5+incompatible/go.mod h1:otzb+WCGbkyDHkqmQmT5YD2WR4BBwUdeQoFo8l/7tVs=
 github.com/emicklei/go-restful/v3 v3.8.0/go.mod h1:6n3XBCmQQb25CM2LCACGz8ukIrRry+4bhvbpWn3mrbc=
 github.com/emicklei/go-restful/v3 v3.9.0/go.mod h1:6n3XBCmQQb25CM2LCACGz8ukIrRry+4bhvbpWn3mrbc=
+github.com/emicklei/proto v1.10.0 h1:pDGyFRVV5RvV+nkBK9iy3q67FBy9Xa7vwrOTE+g5aGw=
+github.com/emicklei/proto v1.10.0/go.mod h1:rn1FgRS/FANiZdD2djyH7TMA9jdRDcYQ9IEN9yvjX0A=
 github.com/emirpasic/gods v1.18.1 h1:FXtiHYKDGKCW2KzwZKx0iC0PQmdlorYgdFG9jPXJ1Bc=
 github.com/emirpasic/gods v1.18.1/go.mod h1:8tpGGwCnJ5H4r6BWwaV6OrWmMoPhUl5jm/FMNAnJvWQ=
 github.com/envoyproxy/go-control-plane v0.9.0/go.mod h1:YTl/9mNaCwkRvm6d1a2C3ymFceY/DCBVvsKhRF0iEA4=
@@ -1013,6 +1019,8 @@ github.com/go-playground/locales v0.13.0/go.mod h1:taPMhCMXrRLJO55olJkUXHZBHCxTM
 github.com/go-playground/universal-translator v0.17.0/go.mod h1:UkSxE5sNxxRwHyU+Scu5vgOQjsIJAF8j9muTVoKLVtA=
 github.com/go-playground/validator/v10 v10.2.0/go.mod h1:uOYAAleCW8F/7oMFd6aG0GOhaH6EGOAJShg8Id5JGkI=
 github.com/go-playground/validator/v10 v10.4.1/go.mod h1:nlOn6nFhuKACm19sB/8EGNn9GlaMV7XkbRSipzJ0Ii4=
+github.com/go-quicktest/qt v1.100.0 h1:I7iSLgIwNp0E0UnSvKJzs7ig0jg/Iq83zsZjtQNW7jY=
+github.com/go-quicktest/qt v1.100.0/go.mod h1:leyLsQ4jksGmF1KaQEyabnqGIiJTbOU5S46QegToEj4=
 github.com/go-resty/resty/v2 v2.1.1-0.20191201195748-d7b97669fe48/go.mod h1:dZGr0i9PLlaaTD4H/hoZIDjQ+r6xq8mgbRzHZf7f2J8=
 github.com/go-sql-driver/mysql v1.7.0/go.mod h1:OXbVy3sEdcQ2Doequ6Z5BW6fXNQTmx+9S1MCJN5yJMI=
 github.com/go-stack/stack v1.8.0/go.mod h1:v0f6uXyyMGvRgIKkXu+yp6POWl0qKG85gN/melR3HDY=
@@ -1494,6 +1502,7 @@ github.com/lib/pq v1.0.0/go.mod h1:5WUZQaWbwv1U+lTReE5YruASi9Al49XbQIvNi/34Woo=
 github.com/lib/pq v1.1.0/go.mod h1:5WUZQaWbwv1U+lTReE5YruASi9Al49XbQIvNi/34Woo=
 github.com/lib/pq v1.2.0/go.mod h1:5WUZQaWbwv1U+lTReE5YruASi9Al49XbQIvNi/34Woo=
 github.com/lib/pq v1.10.2/go.mod h1:AlVN5x4E4T544tWzH6hKfbfQvm3HdbOxrmggDNAPY9o=
+github.com/lib/pq v1.10.7 h1:p7ZhMD+KsSRozJr34udlUrhboJwWAgCg34+/ZZNvZZw=
 github.com/lib/pq v1.10.7/go.mod h1:AlVN5x4E4T544tWzH6hKfbfQvm3HdbOxrmggDNAPY9o=
 github.com/linode/linodego v1.4.0/go.mod h1:PVsRxSlOiJyvG4/scTszpmZDTdgS+to3X6eS8pRrWI8=
 github.com/linode/linodego v1.12.0/go.mod h1:NJlzvlNtdMRRkXb0oN6UWzUkj6t+IBsyveHgZ5Ppjyk=
@@ -1565,6 +1574,8 @@ github.com/mitchellh/go-homedir v1.1.0/go.mod h1:SfyaCUpYCn1Vlf4IUYiD9fPX4A5wJrk
 github.com/mitchellh/go-testing-interface v1.0.0/go.mod h1:kRemZodwjscx+RGhAo8eIhFbs2+BFgRtFPeD/KE+zxI=
 github.com/mitchellh/go-testing-interface v1.14.1/go.mod h1:gfgS7OtZj6MA4U1UrDRp04twqAjfvlZyCfX3sDjEym8=
 github.com/mitchellh/go-wordwrap v1.0.0/go.mod h1:ZXFpozHsX6DPmq2I0TCekCxypsnAUbP2oI0UX1GXzOo=
+github.com/mitchellh/go-wordwrap v1.0.1 h1:TLuKupo69TCn6TQSyGxwI1EblZZEsQ0vMlAFQflz0v0=
+github.com/mitchellh/go-wordwrap v1.0.1/go.mod h1:R62XHJLzvMFRBbcrT7m7WgmE1eOyTSsCt+hzestvNj0=
 github.com/mitchellh/gox v0.4.0/go.mod h1:Sd9lOJ0+aimLBi73mGofS1ycjY8lL3uZM3JPS42BGNg=
 github.com/mitchellh/iochan v1.0.0/go.mod h1:JwYml1nuB7xOzsp52dPpHFffvOCDupsG0QubkSMEySY=
 github.com/mitchellh/mapstructure v0.0.0-20160808181253-ca63d7c062ee/go.mod h1:FVVH3fgwuzCH5S8UJGiWEs2h04kUh9fWfEaFds41c1Y=
@@ -1596,6 +1607,8 @@ github.com/modocache/gover v0.0.0-20171022184752-b58185e213c5/go.mod h1:caMODM3P
 github.com/montanaflynn/stats v0.0.0-20171201202039-1bf9dbcd8cbe/go.mod h1:wL8QJuTMNUDYhXwkmfOly8iTdp5TEcJFWZD2D7SIkUc=
 github.com/montanaflynn/stats v0.6.6/go.mod h1:etXPPgVO6n31NxCd9KQUMvCM+ve0ruNzt6R8Bnaayow=
 github.com/morikuni/aec v1.0.0/go.mod h1:BbKIizmSmc5MMPqRYbxO4ZU0S0+P200+tUnFx7PXmsc=
+github.com/mpvl/unique v0.0.0-20150818121801-cbe035fff7de h1:D5x39vF5KCwKQaw+OC9ZPiLVHXz3UFw2+psEX+gYcto=
+github.com/mpvl/unique v0.0.0-20150818121801-cbe035fff7de/go.mod h1:kJun4WP5gFuHZgRjZUWWuH1DTxCtxbHDOIJsudS8jzY=
 github.com/mrunalp/fileutils v0.5.0/go.mod h1:M1WthSahJixYnrXQl/DFQuteStB1weuxD2QJNHXfbSQ=
 github.com/munnerz/goautoneg v0.0.0-20120707110453-a547fc61f48d/go.mod h1:+n7T8mK8HuQTcFwEeznm/DIxMOiR9yIdICNftLE1DvQ=
 github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822/go.mod h1:+n7T8mK8HuQTcFwEeznm/DIxMOiR9yIdICNftLE1DvQ=
@@ -1774,6 +1787,8 @@ github.com/prometheus/procfs v0.8.0/go.mod h1:z7EfXMXOkbkqb9IINtpCn86r/to3BnA0ua
 github.com/prometheus/prometheus v0.35.0/go.mod h1:7HaLx5kEPKJ0GDgbODG0fZgXbQ8K/XjZNJXQmbmgQlY=
 github.com/prometheus/prometheus v0.42.0/go.mod h1:Pfqb/MLnnR2KK+0vchiaH39jXxvLMBk+3lnIGP4N7Vk=
 github.com/prometheus/tsdb v0.7.1/go.mod h1:qhTCs0VvXwvX/y3TZrWD7rabWM+ijKTux40TwIPHuXU=
+github.com/protocolbuffers/txtpbfmt v0.0.0-20230328191034-3462fbc510c0 h1:sadMIsgmHpEOGbUs6VtHBXRR1OHevnj7hLx9ZcdNGW4=
+github.com/protocolbuffers/txtpbfmt v0.0.0-20230328191034-3462fbc510c0/go.mod h1:jgxiZysxFPM+iWKwQwPR+y+Jvo54ARd4EisXxKYpB5c=
 github.com/rakyll/embedmd v0.0.0-20171029212350-c8060a0752a2/go.mod h1:7jOTMgqac46PZcF54q6l2hkLEG8op93fZu61KmxWDV4=
 github.com/rcrowley/go-metrics v0.0.0-20181016184325-3113b8401b8a/go.mod h1:bCqnVzQkZxMG4s8nGwiZ5l3QUCyqpo9Y+/ZMZ9VjZe4=
 github.com/rogpeppe/fastuuid v0.0.0-20150106093220-6724a57986af/go.mod h1:XWv6SoW27p1b0cqNHllgS5HIMJraePCO15w5zCzIWYg=
diff --git a/internal/tests/integration/datasources_file_test.go b/internal/tests/integration/datasources_file_test.go
index 67d6b895..9af8503b 100644
--- a/internal/tests/integration/datasources_file_test.go
+++ b/internal/tests/integration/datasources_file_test.go
@@ -31,6 +31,24 @@ FOO.BAR = "values can be double-quoted, and shell\nescapes are supported"
 BAZ = "variable expansion: ${FOO}"
 QUX='single quotes ignore $variables'
 `,
+			"test.cue": `package core
+
+import "regexp"
+
+matches: regexp.FindSubmatch(#"^([^:]*):(\d+)$"#, "localhost:443")
+
+one: 1
+two: 2
+
+// A field using quotes.
+"two-and-a-half": 2.5
+
+list: [
+	1,
+	2,
+	3,
+]
+`,
 		}),
 		fs.WithDir("sortorder", fs.WithFiles(map[string]string{
 			"template": `aws_zones = {
@@ -120,7 +138,7 @@ func TestDatasources_File(t *testing.T) {
 
 	o, e, err = cmd(t, "-d", "dir="+tmpDir.Path()+"/",
 		"-i", `{{ range (ds "dir") }}{{ . }} {{ end }}`).run()
-	assertSuccess(t, o, e, err, "ajsonfile config.json config.yml config2.yml encrypted.json foo.csv sortorder test.env ")
+	assertSuccess(t, o, e, err, "ajsonfile config.json config.yml config2.yml encrypted.json foo.csv sortorder test.cue test.env ")
 
 	o, e, err = cmd(t, "-d", "enc="+tmpDir.Join("encrypted.json"),
 		"-i", `{{ (ds "enc").password }}`).
@@ -149,6 +167,14 @@ func TestDatasources_File(t *testing.T) {
   "FOO.BAR": "values can be double-quoted, and shell\nescapes are supported",
   "QUX": "single quotes ignore $variables"
 }`)
+
+	o, e, err = cmd(t, "-d", "cuedata="+tmpDir.Join("test.cue"),
+		"-i", `{{ (ds "cuedata").matches | data.ToJSONPretty "  " }}`).run()
+	assertSuccess(t, o, e, err, `[
+  "localhost:443",
+  "localhost",
+  "443"
+]`)
 }
 
 func TestDatasources_File_Directory(t *testing.T) {