Patterns

Intersect reasons over patterns as languages, not over the filesystem. parse splits a path-like string on / and takes each segment as a glob token, verbatim. There is no inference — no directory/file heuristic, no ambiguity error. A single trailing separator is normalized off, so src/api/ equals src/api; nothing else is collapsed.

The rule: exact match vs. subtree

A pattern with no wildcards is an exact-path match. A bare path is exactly that path, not the files beneath it. You opt into a subtree explicitly with /**.

import { intersects } from "@sksizer/intersect";

// No wildcards → an exact-path match. Opt into a subtree explicitly with `**`.
intersects("src/siteA/components", "src/siteA/components");
intersects("src/siteA/components", "src/siteA/components/Button.vue");
intersects("src/siteA/components/**", "src/siteA/components/Button.vue");
intersects("**/*.vue", "src/siteA/components/Button.vue");

A	B	Result	Why
`src/siteA/components`	`src/siteA/components`	`true`	same path
`src/siteA/components`	`src/siteA/components/Button.vue`	`false`	a child, not the path
`src/siteA/components/**`	`src/siteA/components/Button.vue`	`true`	explicit `**` subtree
`*/.vue`	`src/siteA/components/Button.vue`	`true`	wildcards work as usual

The dialect

Each segment between separators is a glob token. / is a distinguished symbol that the per-segment wildcards never cross.

Token	Matches
`*`	any run of characters within one segment (`[^/]*`)
`?`	exactly one character within a segment
`**`	zero or more whole segments — the only token that crosses `/`
`{a,b}`	alternation: `a` or `b` (e.g. `*.{vue,html,jsx}`)
`[abc]`, `[a-z]`	one character from the class
`[!abc]`	one character NOT in the class
literal text	itself, verbatim

Options

Matching semantics are shared by the segment core and the path API. All default off except globstarMatchesZero.

Option	Default	Effect
`caseInsensitive`	`false`	Match paths ignoring ASCII case.
`dot`	`false`	Let ``/`*` match a leading-dot segment. Off, so dotfiles are excluded.
`globstarMatchesZero`	`true`	Let a globstar span zero segments, so `a/**/b` matches `a/b`.

import { intersects } from "@sksizer/intersect";

intersects("SRC/**", "src/api.ts", { caseInsensitive: true });
intersects("*", ".env");
intersects("*", ".env", { dot: true });
intersects("a/**/b", "a/b", { globstarMatchesZero: true });

A	B	Options	Result	Why
`SRC/**`	`src/api.ts`	`{ caseInsensitive: true }`	`true`	ASCII case ignored
`*`	`.env`	—	`false`	dotfiles excluded by default
`*`	`.env`	`{ dot: true }`	`true`	dot opt-in
`a/**/b`	`a/b`	`{ globstarMatchesZero: true }`	`true`	globstar spans zero segments

Pattern-level negation (!pat, gitignore re-includes) is out of v1 — it needs language complement. Class-negation [!abc] is fine, since it is per-character, not per-pattern.