yqutil: fix to preserve line breaks

.github/workflows/test.yml

@@ -90,6 +90,10 @@ jobs:
       run: make
     - name: Install
       run: sudo make install
+    - name: Verify templates match `limactl edit` format
+      run: |
+        find examples -name '*.yaml' -exec limactl edit --set 'del(.nothing)' {} \;
+        git diff-index --exit-code HEAD
     - name: Uninstall
       run: sudo make uninstall
 

examples/buildkit.yaml

@@ -5,11 +5,11 @@
 # $ export BUILDKIT_HOST=$(limactl list buildkit --format 'unix://{{.Dir}}/sock/buildkitd.sock')
 # $ buildctl debug workers
 message: |
- To run `buildkit` on the host (assumes buildctl is installed), run the following commands:
- -------
- export BUILDKIT_HOST="unix://{{.Dir}}/sock/buildkitd.sock"
- buildctl debug workers
- -------
+  To run `buildkit` on the host (assumes buildctl is installed), run the following commands:
+  -------
+  export BUILDKIT_HOST="unix://{{.Dir}}/sock/buildkitd.sock"
+  buildctl debug workers
+  -------
 images:
 # Try to use release-yyyyMMdd image if available. Note that release-yyyyMMdd will be removed after several months.
 - location: "https://cloud-images.ubuntu.com/releases/24.04/release-20240821/ubuntu-24.04-server-cloudimg-amd64.img"

examples/default.yaml

@@ -264,10 +264,10 @@ containerd:
 # Setting of instructions is supported like this: "qemu64,+ssse3".
 # 🟢 Builtin default: hard-coded arch map with type (see the output of `limactl info | jq .defaultTemplate.cpuType`)
 cpuType:
-  # aarch64: "cortex-a72" # (or "host" when running on aarch64 host)
-  # armv7l: "cortex-a7" # (or "host" when running on armv7l host)
-  # riscv64: "rv64" # (or "host" when running on riscv64 host)
-  # x86_64: "qemu64" # (or "host,-pdpe1gb" when running on x86_64 host)
+#   aarch64: "cortex-a72" # (or "host" when running on aarch64 host)
+#   armv7l: "cortex-a7" # (or "host" when running on armv7l host)
+#   riscv64: "rv64" # (or "host" when running on riscv64 host)
+#   x86_64: "qemu64" # (or "host,-pdpe1gb" when running on x86_64 host)
 
 rosetta:
   # Enable Rosetta for Linux (EXPERIMENTAL; will graduate from experimental in Lima v1.0).
@@ -456,8 +456,8 @@ hostResolver:
   # predefined to specify the gateway address to the host.
   # 🟢 Builtin default: null
   hosts:
-    # guest.name: 127.1.1.1
-    # host.name: host.lima.internal
+  #   guest.name: 127.1.1.1
+  #   host.name: host.lima.internal
 
 # If hostResolver.enabled is false, then the following rules apply for configuring dns:
 # Explicitly set DNS addresses for qemu user-mode networking. By default qemu picks *one*

pkg/yqutil/yqutil.go

@@ -6,6 +6,7 @@ import (
 	"os"
 	"strings"
 
+	"github.com/google/yamlfmt"
 	"github.com/google/yamlfmt/formatters/basic"
 	"github.com/mikefarah/yq/v4/pkg/yqlib"
 	"github.com/sirupsen/logrus"
@@ -15,13 +16,26 @@ import (
 // EvaluateExpression evaluates the yq expression, and returns the modified yaml.
 func EvaluateExpression(expression string, content []byte) ([]byte, error) {
 	logrus.Debugf("Evaluating yq expression: %q", expression)
+	formatter, err := yamlfmtBasicFormatter()
+	if err != nil {
+		return nil, err
+	}
+	// `ApplyFeatures()` is being called directly before passing content to `yqlib`.
+	// This results in `ApplyFeatures()` being called twice with `FeatureApplyBefore`:
+	// once here and once inside `formatter.Format`.
+	// Currently, calling `ApplyFeatures()` with `FeatureApplyBefore` twice is not an issue,
+	// but future changes to `yamlfmt` might cause problems if it is called twice.
+	contentModified, err := formatter.Features.ApplyFeatures(content, yamlfmt.FeatureApplyBefore)
+	if err != nil {
+		return nil, err
+	}
 	tmpYAMLFile, err := os.CreateTemp("", "lima-yq-*.yaml")
 	if err != nil {
 		return nil, err
 	}
 	tmpYAMLPath := tmpYAMLFile.Name()
 	defer os.RemoveAll(tmpYAMLPath)
-	_, err = tmpYAMLFile.Write(content)
+	_, err = tmpYAMLFile.Write(contentModified)
 	if err != nil {
 		tmpYAMLFile.Close()
 		return nil, err
@@ -70,7 +84,7 @@ func EvaluateExpression(expression string, content []byte) ([]byte, error) {
 		return nil, err
 	}
 
-	return yamlfmt(out.Bytes())
+	return formatter.Format(out.Bytes())
 }
 
 func Join(yqExprs []string) string {
@@ -80,17 +94,23 @@ func Join(yqExprs []string) string {
 	return strings.Join(yqExprs, " | ")
 }
 
-func yamlfmt(content []byte) ([]byte, error) {
+func yamlfmtBasicFormatter() (*basic.BasicFormatter, error) {
 	factory := basic.BasicFormatterFactory{}
 	config := map[string]interface{}{
-		"indentless_arrays":  true,
-		"line_ending":        "lf", // prefer LF even on Windows
-		"pad_line_comments":  2,
-		"retain_line_breaks": true, // does not affect to the output because yq removes empty lines before formatting
+		"indentless_arrays":         true,
+		"line_ending":               "lf", // prefer LF even on Windows
+		"pad_line_comments":         2,
+		"retain_line_breaks":        true,
+		"retain_line_breaks_single": false,
 	}
+
 	formatter, err := factory.NewFormatter(config)
 	if err != nil {
 		return nil, err
 	}
-	return formatter.Format(content)
+	basicFormatter, ok := formatter.(*basic.BasicFormatter)
+	if !ok {
+		return nil, fmt.Errorf("unexpected formatter type: %T", formatter)
+	}
+	return basicFormatter, nil
 }

pkg/yqutil/yqutil_test.go

@@ -19,6 +19,7 @@ memory: null
 	expected := `
 # CPUs
 cpus: 2
+
 # Memory size
 memory: 2GiB
 `