Diff Two Directory Trees as a Mermaid Flowchart — tree_diff

Builds both trees with the same options and renders the difference as a Mermaid flowchart: nodes only in after are green, nodes only in before are red and dashed, and unchanged nodes are neutral. Nodes are matched by their path relative to each tree root.

Usage

tree_diff_mermaid(
  before,
  after,
  direction = c("TD", "LR", "RL", "BT"),
  file = NULL,
  ...
)

Arguments

before: Character. Directory path for the "before" tree.
after: Character. Directory path for the "after" tree.
direction: Character. Flowchart direction: "TD" (top-down), "LR" (left-right), "RL", or "BT".
file: Character or NULL. If given, the diagram text is written to this file with writeLines().
...: Additional arguments passed to build_tree() for both trees (e.g. ignore, max_depth, show_hidden, prune).

Value

Invisibly, the diagram text as a single string (or file when file is given).

Examples

old <- file.path(tempdir(), "printtree-diff-old")
new <- file.path(tempdir(), "printtree-diff-new")
for (d in c(old, new)) {
  if (dir.exists(d)) unlink(d, recursive = TRUE)
  dir.create(d, recursive = TRUE)
}
file.create(file.path(old, "gone.txt"))
#> [1] TRUE
file.create(file.path(new, "added.txt"))
#> [1] TRUE
file.create(file.path(old, "kept.txt"))
#> [1] TRUE
file.create(file.path(new, "kept.txt"))
#> [1] TRUE

cat(tree_diff_mermaid(old, new))
#> flowchart TD
#>     n1(["printtree-diff-new/"])
#>     n2["added.txt"]
#>     n3["kept.txt"]
#>     n4["gone.txt"]
#>     classDef ptAdd fill:#dcfce7,stroke:#15803d;
#>     classDef ptDel fill:#fee2e2,stroke:#b91c1c,stroke-dasharray:5 5;
#>     class n2 ptAdd;
#>     class n4 ptDel;
#>     n1 --> n2
#>     n1 --> n3
#>     n1 --> n4

# Left-to-right layout
cat(tree_diff_mermaid(old, new, direction = "LR"))
#> flowchart LR
#>     n1(["printtree-diff-new/"])
#>     n2["added.txt"]
#>     n3["kept.txt"]
#>     n4["gone.txt"]
#>     classDef ptAdd fill:#dcfce7,stroke:#15803d;
#>     classDef ptDel fill:#fee2e2,stroke:#b91c1c,stroke-dasharray:5 5;
#>     class n2 ptAdd;
#>     class n4 ptDel;
#>     n1 --> n2
#>     n1 --> n3
#>     n1 --> n4