Add file embedding support

[karngyan]

Add file embedding support

This PR adds the ability to embed file contents directly into generated Go code using the file: prefix in TOML values.

Features

• File embedding: Use file:path/to/file in TOML to embed file contents as []byte in generated code
• Size limits: Configurable max file size (default 1MB) via --max-file-size flag
• Path resolution: File paths are relative to the TOML file location
• Validation: Files are validated at generation time for existence and size limits

Refactoring

• Split generator.go into focused modules:
  • file_handler.go - file reading and embedding
  • struct_gen.go - struct generation logic
  • validation.go - validation helpers
  • value_writer.go - value serialization

Use Cases

• TLS certificates and keys
• SQL schemas
• Template files
• Small assets (logos, icons)
• Configuration snippets

Files are embedded as hex byte arrays at generation time, making binaries self-contained with no runtime I/O needed.

[Copilot]

Pull Request Overview

This PR adds comprehensive file embedding support to the cfgx tool, allowing TOML values to reference external files using the file: prefix syntax. When generation occurs, these files are read and embedded as []byte arrays in the generated Go code, creating self-contained binaries.

Key changes:

• File embedding using file:path/to/file syntax in TOML values
• Configurable size limits with --max-file-size flag (default 1MB)
• Code refactoring to split generator.go into focused modules

Reviewed Changes

Copilot reviewed 19 out of 20 changed files in this pull request and generated 4 comments.

Show a summary per file

File	Description
readme.md	Added comprehensive documentation for file embedding feature with examples and use cases
internal/generator/generator.go	Refactored to move most functionality to focused modules, added file validation support
internal/generator/file_handler.go	New module handling file reference detection and content loading with size validation
internal/generator/value_writer.go	New module for Go value serialization with file embedding and duration support
internal/generator/struct_gen.go	New module containing struct generation logic moved from main generator
internal/generator/validation.go	New module for validation helpers including time import detection
cmd/cfgx/main.go	Added --max-file-size flag with human-readable size parsing
cfgx.go	Updated public API to support file embedding with new options
testdata/files/	Added test files for validating file embedding functionality
example/config/	Updated example to demonstrate file embedding with certificate

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[github-actions]

📊 Code Coverage Report

total:									(statements)			67.2%

Coverage by file

github.com/gomantics/cfgx/cfgx.go:82:					GenerateFromFile		77.1%
github.com/gomantics/cfgx/cfgx.go:168:					Generate			100.0%
github.com/gomantics/cfgx/cfgx.go:184:					GenerateWithOptions		66.7%
github.com/gomantics/cfgx/cmd/cfgx/main.go:30:				main				0.0%
github.com/gomantics/cfgx/cmd/cfgx/main.go:38:				parseFileSize			0.0%
github.com/gomantics/cfgx/cmd/cfgx/main.go:140:				init				0.0%
github.com/gomantics/cfgx/internal/envoverride/envoverride.go:13:	Apply				50.0%
github.com/gomantics/cfgx/internal/envoverride/envoverride.go:40:	applyNested			88.2%
github.com/gomantics/cfgx/internal/envoverride/envoverride.go:79:	convertValue			93.3%
github.com/gomantics/cfgx/internal/envoverride/envoverride.go:111:	convertArray			88.9%
github.com/gomantics/cfgx/internal/generator/file_handler.go:11:	isFileReference			100.0%
github.com/gomantics/cfgx/internal/generator/file_handler.go:18:	loadFileContent			81.2%
github.com/gomantics/cfgx/internal/generator/generator.go:25:		WithPackageName			100.0%
github.com/gomantics/cfgx/internal/generator/generator.go:32:		WithEnvOverride			0.0%
github.com/gomantics/cfgx/internal/generator/generator.go:39:		WithInputDir			100.0%
github.com/gomantics/cfgx/internal/generator/generator.go:46:		WithMaxFileSize			100.0%
github.com/gomantics/cfgx/internal/generator/generator.go:53:		New				100.0%
github.com/gomantics/cfgx/internal/generator/generator.go:68:		stripSuffix			40.0%
github.com/gomantics/cfgx/internal/generator/generator.go:79:		Generate			88.2%
github.com/gomantics/cfgx/internal/generator/struct_gen.go:24:		generateStructsAndVars		63.8%
github.com/gomantics/cfgx/internal/generator/struct_gen.go:128:		collectNestedStructs		57.1%
github.com/gomantics/cfgx/internal/generator/struct_gen.go:166:		generateStruct			89.5%
github.com/gomantics/cfgx/internal/generator/struct_gen.go:208:		generateStructInit		85.2%
github.com/gomantics/cfgx/internal/generator/struct_gen.go:272:		writeArrayOfTablesInit		58.8%
github.com/gomantics/cfgx/internal/generator/struct_gen.go:317:		writeArrayOfStructs		0.0%
github.com/gomantics/cfgx/internal/generator/validation.go:10:		validateFileReferences		100.0%
github.com/gomantics/cfgx/internal/generator/validation.go:20:		validateFileReferencesValue	84.6%
github.com/gomantics/cfgx/internal/generator/validation.go:51:		needsTimeImport			100.0%
github.com/gomantics/cfgx/internal/generator/validation.go:60:		needsTimeImportValue		88.9%
github.com/gomantics/cfgx/internal/generator/validation.go:82:		isDurationString		100.0%
github.com/gomantics/cfgx/internal/generator/value_writer.go:17:	toGoType			94.1%
github.com/gomantics/cfgx/internal/generator/value_writer.go:61:	writeValue			100.0%
github.com/gomantics/cfgx/internal/generator/value_writer.go:66:	writeValueWithIndent		76.5%
github.com/gomantics/cfgx/internal/generator/value_writer.go:105:	writeByteArrayLiteral		88.2%
github.com/gomantics/cfgx/internal/generator/value_writer.go:141:	writeDurationLiteral		80.0%
github.com/gomantics/cfgx/internal/generator/value_writer.go:197:	writeArray			80.0%
github.com/gomantics/cfgx/internal/pkgutil/pkgutil.go:11:		InferName			63.6%
total:									(statements)			67.2%

[Copilot]

Pull Request Overview

Copilot reviewed 19 out of 20 changed files in this pull request and generated no new comments.

Comments suppressed due to low confidence (3)

internal/generator/value_writer.go:1

• The writeValueWithIndent call should use the correct value parameter - it's passing 'value' instead of 'val' which is the []any slice being processed.

package generator

internal/generator/value_writer.go:1

• The writeValueWithIndent call should use the correct value parameter - it's passing 'value' instead of 'val' which is the []any slice being processed.

package generator

internal/generator/value_writer.go:1

• Type mismatch: writeArrayOfStructs expects []any or []map[string]any, but val is []map[string]any. The function should be called with the correct type.

package generator

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