diff

Documentation

Index

• func IsGeneratedFile(repoPath, path string) bool
• func ShowAtRef(repoPath, ref, repoRelPath string) ([]byte, error)
• type ChangedRegion
• type FileChange
  • func (fc FileChange) ContainsLine(line int) bool
  • func (fc FileChange) IsNew() bool
  • func (fc FileChange) OverlapsRange(start, end int) bool
• type Filter
• type Result
  • func CollectPaths(repoPath string, paths []string, filter Filter) (*Result, error)
  • func Parse(repoPath, baseBranch string, filter Filter) (*Result, error)
  • func (r Result) ChangedPackages() []string
  • func (r Result) FilesByPackage() map[string][]FileChange

Functions

func IsGeneratedFile

func IsGeneratedFile(repoPath, path string) bool

IsGeneratedFile reports whether the file contains a standard generated-code marker near the top of the file, such as "Code generated ... DO NOT EDIT". Read errors return false so file selection stays conservative.

func ShowAtRef

func ShowAtRef(repoPath, ref, repoRelPath string) ([]byte, error)

ShowAtRef returns the bytes of repoRelPath at the given git ref, or (nil, nil) if the path didn't exist there. Other failures (bad ref, not a git repo) bubble up as errors. Used by delta-gating analyzers to compare a changed file's metric against its pre-change baseline.

`git show ref:path` exits 128 for several distinct conditions: path absent in the tree, ref unknown, not a git repo. Only the first should turn into the "no baseline" signal — the others must surface as errors so a broken CI config doesn't silently weaken the gate. We disambiguate on stderr.

Types

type ChangedRegion

type ChangedRegion struct {
	StartLine int
	EndLine   int
}

ChangedRegion represents a contiguous range of changed lines in a file.

type FileChange

type FileChange struct {
	Path    string
	Regions []ChangedRegion
}

FileChange represents changes to a single file in the diff.

func (FileChange) ContainsLine

func (fc FileChange) ContainsLine(line int) bool

ContainsLine returns true if the given line number falls within a changed region.

func (FileChange) IsNew

func (fc FileChange) IsNew() bool

IsNew returns true if the entire file is new (single region from line 1).

func (FileChange) OverlapsRange

func (fc FileChange) OverlapsRange(start, end int) bool

OverlapsRange returns true if any changed region overlaps [start, end].

type Filter

type Filter struct {
	// DiffGlobs is passed to `git diff -- <globs>` to restrict the raw diff
	// to language source files.
	DiffGlobs []string
	// Includes reports whether an analyzable source path (extension matches,
	// not a test file) belongs to the caller's language.
	Includes func(path string) bool
}

Filter describes the subset of the diff the caller cares about. It is a narrower shape than lang.FileFilter so the diff package doesn't have to import lang (which would pull the full analyzer stack). Callers (usually cmd/diffguard) construct a Filter from their chosen language's lang.FileFilter and pass it here.

type Result

type Result struct {
	BaseBranch string
	// MergeBase is the resolved commit SHA of merge-base(BaseBranch, HEAD).
	// Populated by Parse; empty in refactoring mode (CollectPaths). Used by
	// delta-gating analyzers to fetch pre-change file content via `git show`.
	MergeBase string
	Files     []FileChange
}

Result holds all changed source files parsed from a git diff.

func CollectPaths

func CollectPaths(repoPath string, paths []string, filter Filter) (*Result, error)

CollectPaths builds a Result by treating each analyzable source file under the given paths as fully changed. Useful for refactoring mode where you want to analyze entire files rather than diffed regions only.

paths may contain individual files or directories (walked recursively). Files that fail filter.Includes are excluded — test files and non-source files never show up in the result.

func Parse

func Parse(repoPath, baseBranch string, filter Filter) (*Result, error)

Parse runs `git diff` against the merge-base of baseBranch..HEAD and returns the changed files that pass the filter. The filter is also used to restrict the raw `git diff` output via -- globs so the parser never has to see files from other languages.

func (Result) ChangedPackages

func (r Result) ChangedPackages() []string

ChangedPackages returns the unique set of package directories with changes.

func (Result) FilesByPackage

func (r Result) FilesByPackage() map[string][]FileChange

FilesByPackage groups changed files by their package directory.