bufio.echo

; std/bufio — line splitting helpers (thin; pure Echo over strings).
;
; Public API:
;   lines(s) — list of lines (split on \n)
;   read_lines(path) — result of lines from whole-file read, or ! io err
;
; Suite: xo test std/bufio.echo

/ std/str
/ std/fs
/ std/list
/ std/test

$ lines = (s) {
    ^ str.split(s, "\n")
}

$ read_lines = (path) {
    | fs.read(path) {
        $ b {
            $ t = str.from_bytes(b)
            ^ lines(t)
        }
        ! e {
            ! e
        }
    }
}

test.it("lines_basic", () {
    $ ls = lines("a\nb\nc")
    test.eq(list.len(ls), 3)
    | list.get(ls, 0) {
        $ a {
            test.eq(a, "a")
        }
        ! e {
            test.fail(e)
        }
    }
    | list.get(ls, 1) {
        $ b {
            test.eq(b, "b")
        }
        ! e {
            test.fail(e)
        }
    }
})

test.it("lines_len", () {
    $ ls = lines("x\ny")
    test.eq(list.len(ls), 2)
})

test.it("read_lines_missing", () {
    | read_lines("/tmp/echo_bufio_absent_zzz") {
        $ ls {
            test.fail("expected err")
        }
        ! e {
            test.eq(e, "read failed")
        }
    }
})

test.it("read_lines_file", () {
    $ p = fs.join(fs.temp_dir(), "echo_bufio_suite.txt")
    | fs.write(p, "a\nb") {
        $ ok {}
        ! e {
            test.fail(e)
        }
    }
    | read_lines(p) {
        $ ls {
            test.eq(list.len(ls), 2)
            | list.get(ls, 0) {
                $ a {
                    test.eq(a, "a")
                }
                ! e {
                    test.fail(e)
                }
            }
        }
        ! e {
            test.fail(e)
        }
    }
    | fs.remove(p) {
        $ ok {}
        ! e {}
    }
})

\ lines, read_lines