feature: read configuration from file

.goreleaser.yaml

@@ -59,4 +59,4 @@ changelog:
       order: 999
   filters:
     exclude:
-      - "^Merge pull request #" # exclude merge commits
+      - "^Merge" # exclude merge commits

.pre-commit-config.yaml

@@ -1,6 +1,6 @@
 repos:
   - repo: https://github.com/losisin/helm-values-schema-json
-    rev: v1.4.1
+    rev: v1.5.0
     hooks:
       - id: helm-schema
         args:

README.md

@@ -58,7 +58,7 @@ First [install pre-commit](https://pre-commit.com/#install) and then create or u
 ```yaml
 repos:
   - repo: https://github.com/losisin/helm-values-schema-json
-    rev: v1.4.1
+    rev: v1.5.0
     hooks:
       - id: helm-schema
         args: ["-input", "values.yaml"]
@@ -89,7 +89,7 @@ This is a great tool for adding git hooks to your project. You can find it's doc
 
 ```bash
 $ helm schema -help
-usage: helm schema [-input STR] [-draft INT] [-output STR]
+Usage: helm schema [options...] <arguments>
   -draft int
     	Draft version (4, 6, 7, 2019, or 2020) (default 2020)
   -indent int
@@ -108,7 +108,35 @@ usage: helm schema [-input STR] [-draft INT] [-output STR]
     	JSON schema title
 ```
 
-### Basic
+### Configuration file
+
+This plugin will look for it's configuration file called `schema.yaml` in the current working directory. All options available from CLI can be set in this file. Example:
+
+```yaml
+# Required
+input:
+  - schema.yaml
+
+draft: 2020
+indent: 4
+output: values.schema.json
+
+schemaRoot:
+  id: https://example.com/schema
+  title: Helm Values Schema
+  description: Schema for Helm values
+  additionalProperties: true
+```
+
+Then, just run the plugin without any arguments:
+
+```bash
+$ helm schema
+```
+
+### CLI
+
+#### Basic
 
 In most cases you will want to run the plugin with default options:
 
@@ -118,9 +146,9 @@ $ helm schema -input values.yaml
 
 This will read `values.yaml`, set draft version to `2020-12` and save outpout to `values.schema.json`.
 
-### Extended
+#### Extended
 
-#### Multiple values files
+##### Multiple values files
 
 Merge multiple values files, set json-schema draft version explicitly and save output to `my.schema.json`:
 
@@ -217,7 +245,7 @@ Output will be something like this:
 }
 ```
 
-#### Root JSON object properties
+##### Root JSON object properties
 
 Adding ID, title and description to the schema:
 

main.go

@@ -9,16 +9,31 @@ import (
 )
 
 func main() {
-	conf, output, err := pkg.ParseFlags(os.Args[0], os.Args[1:])
+	// Load configuration from a YAML file
+	fileConfig, err := pkg.LoadConfig("schema.yaml")
+	if err != nil {
+		fmt.Println("Error loading config file:", err)
+	}
+
+	// Parse CLI flags
+	flagConfig, output, err := pkg.ParseFlags(os.Args[0], os.Args[1:])
 	if err == flag.ErrHelp {
 		fmt.Println(output)
 		return
 	} else if err != nil {
-		fmt.Println("Error:", output)
+		fmt.Println("Error parsing flags:", output)
 		return
 	}
 
-	err = pkg.GenerateJsonSchema(conf)
+	// Merge configurations, giving precedence to CLI flags
+	var finalConfig *pkg.Config
+	if fileConfig != nil {
+		finalConfig = pkg.MergeConfig(fileConfig, flagConfig)
+	} else {
+		finalConfig = flagConfig
+	}
+
+	err = pkg.GenerateJsonSchema(finalConfig)
 	if err != nil {
 		fmt.Println("Error:", err)
 	}

main_test.go

@@ -3,6 +3,7 @@ package main
 import (
 	"bytes"
 	"io"
+	"log"
 	"os"
 	"testing"
 
@@ -13,6 +14,8 @@ func TestMain(t *testing.T) {
 	tests := []struct {
 		name          string
 		args          []string
+		setup         func()
+		cleanup       func()
 		expectedError string
 		expectedOut   string
 	}{
@@ -40,14 +43,48 @@ func TestMain(t *testing.T) {
 			expectedOut:   "error reading YAML file(s)",
 			expectedError: "",
 		},
+		{
+			name: "ErrorLoadingConfigFile",
+			args: []string{"schema", "-input", "testdata/basic.yaml"},
+			setup: func() {
+				if _, err := os.Stat("schema.yaml"); err == nil {
+					if err := os.Rename("schema.yaml", "schema.yaml.bak"); err != nil {
+						log.Fatalf("Error renaming file: %v", err)
+					}
+				}
+
+				file, _ := os.Create("schema.yaml")
+				defer file.Close()
+				if _, err := file.WriteString("draft: invalid\n"); err != nil {
+					log.Fatalf("Error writing to file: %v", err)
+				}
+			},
+			cleanup: func() {
+				if _, err := os.Stat("schema.yaml.bak"); err == nil {
+					os.Remove("schema.yaml")
+					if err := os.Rename("schema.yaml.bak", "schema.yaml"); err != nil {
+						log.Fatalf("Error renaming file: %v", err)
+					}
+				} else {
+					os.Remove("schema.yaml")
+				}
+			},
+			expectedOut:   "",
+			expectedError: "Error loading config file",
+		},
 	}
 
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
 			originalArgs := os.Args
 			originalStdout := os.Stdout
 
-			defer os.Remove("values.schema.json")
+			if tt.setup != nil {
+				tt.setup()
+			}
+			if tt.cleanup != nil {
+				defer tt.cleanup()
+			}
 
 			r, w, _ := os.Pipe()
 			os.Stdout = w
@@ -70,9 +107,9 @@ func TestMain(t *testing.T) {
 
 			out := buf.String()
 
-			assert.Contains(t, out, tt.expectedOut)
-			if tt.expectedError != "" {
-				assert.Contains(t, out, tt.expectedError)
+			assert.Contains(t, out, tt.expectedError)
+			if tt.expectedOut != "" {
+				assert.Contains(t, out, tt.expectedOut)
 			}
 		})
 	}

pkg/cmd.go

@@ -4,32 +4,102 @@ import (
 	"bytes"
 	"flag"
 	"fmt"
+	"os"
+
+	"gopkg.in/yaml.v3"
 )
 
 // Parse flags
-func ParseFlags(progname string, args []string) (config *Config, output string, err error) {
+func ParseFlags(progname string, args []string) (*Config, string, error) {
 	flags := flag.NewFlagSet(progname, flag.ContinueOnError)
 	var buf bytes.Buffer
 	flags.SetOutput(&buf)
 
-	var conf Config
-	flags.Var(&conf.input, "input", "Multiple yaml files as inputs (comma-separated)")
-	flags.StringVar(&conf.outputPath, "output", "values.schema.json", "Output file path")
-	flags.IntVar(&conf.draft, "draft", 2020, "Draft version (4, 6, 7, 2019, or 2020)")
-	flags.IntVar(&conf.indent, "indent", 4, "Indentation spaces (even number)")
+	conf := &Config{}
+	flags.Var(&conf.Input, "input", "Multiple yaml files as inputs (comma-separated)")
+	flags.StringVar(&conf.OutputPath, "output", "values.schema.json", "Output file path")
+	flags.IntVar(&conf.Draft, "draft", 2020, "Draft version (4, 6, 7, 2019, or 2020)")
+	flags.IntVar(&conf.Indent, "indent", 4, "Indentation spaces (even number)")
 
 	// Nested SchemaRoot flags
 	flags.StringVar(&conf.SchemaRoot.ID, "schemaRoot.id", "", "JSON schema ID")
 	flags.StringVar(&conf.SchemaRoot.Title, "schemaRoot.title", "", "JSON schema title")
 	flags.StringVar(&conf.SchemaRoot.Description, "schemaRoot.description", "", "JSON schema description")
-	flags.Var(&conf.SchemaRoot.AdditionalProperties, "schemaRoot.additionalProperties", "JSON schema additional properties (true/false)")
+	flags.Var(&conf.SchemaRoot.AdditionalProperties, "schemaRoot.additionalProperties", "Allow additional properties")
 
-	err = flags.Parse(args)
+	err := flags.Parse(args)
 	if err != nil {
-		fmt.Println("Usage: helm schema [-input STR] [-draft INT] [-output STR]")
+		fmt.Println("Usage: helm schema [options...] <arguments>")
 		return nil, buf.String(), err
 	}
 
-	conf.args = flags.Args()
-	return &conf, buf.String(), nil
+	// Mark fields as set if they were provided as flags
+	flags.Visit(func(f *flag.Flag) {
+		switch f.Name {
+		case "output":
+			conf.OutputPathSet = true
+		case "draft":
+			conf.DraftSet = true
+		case "indent":
+			conf.IndentSet = true
+		}
+	})
+
+	conf.Args = flags.Args()
+	return conf, buf.String(), nil
+}
+
+// LoadConfig loads configuration from a YAML file
+var readFileFunc = os.ReadFile
+
+func LoadConfig(configPath string) (*Config, error) {
+	data, err := readFileFunc(configPath)
+	if err != nil {
+		if os.IsNotExist(err) {
+			// Return an empty config if the file does not exist
+			return &Config{}, nil
+		}
+		return nil, err
+	}
+
+	var config Config
+	err = yaml.Unmarshal(data, &config)
+	if err != nil {
+		return nil, err
+	}
+
+	return &config, nil
+}
+
+// MergeConfig merges CLI flags into the configuration file values, giving precedence to CLI flags
+func MergeConfig(fileConfig, flagConfig *Config) *Config {
+	mergedConfig := *fileConfig
+
+	if len(flagConfig.Input) > 0 {
+		mergedConfig.Input = flagConfig.Input
+	}
+	if flagConfig.OutputPathSet || mergedConfig.OutputPath == "" {
+		mergedConfig.OutputPath = flagConfig.OutputPath
+	}
+	if flagConfig.DraftSet || mergedConfig.Draft == 0 {
+		mergedConfig.Draft = flagConfig.Draft
+	}
+	if flagConfig.IndentSet || mergedConfig.Indent == 0 {
+		mergedConfig.Indent = flagConfig.Indent
+	}
+	if flagConfig.SchemaRoot.ID != "" {
+		mergedConfig.SchemaRoot.ID = flagConfig.SchemaRoot.ID
+	}
+	if flagConfig.SchemaRoot.Title != "" {
+		mergedConfig.SchemaRoot.Title = flagConfig.SchemaRoot.Title
+	}
+	if flagConfig.SchemaRoot.Description != "" {
+		mergedConfig.SchemaRoot.Description = flagConfig.SchemaRoot.Description
+	}
+	if flagConfig.SchemaRoot.AdditionalProperties.IsSet() {
+		mergedConfig.SchemaRoot.AdditionalProperties = flagConfig.SchemaRoot.AdditionalProperties
+	}
+	mergedConfig.Args = flagConfig.Args
+
+	return &mergedConfig
 }