cli: add support for rendered links

Add a function to create rendered links for the terminal, and logic
to ignore anything but the text when calculating the length or
printing to a non-tty stdout

Signed-off-by: Renan Rodrigo <[email protected]>

uaclient/cli/formatter.py

@@ -10,6 +10,8 @@
 from uaclient.messages import TxtColor
 
 COLOR_FORMATTING_PATTERN = r"\033\[.*?m"
+LINK_START_PATTERN = r"\033]8;;.+?\033\\+"
+LINK_END = "\033]8;;\033\\"
 UTF8_ALTERNATIVES = {
     "—": "-",
     "✘": "x",
@@ -56,8 +58,18 @@ def disable_suggestions(cls) -> None:
 ProOutputFormatterConfig.init(cfg=UAConfig())
 
 
-def len_no_color(text: str) -> int:
-    return len(re.sub(COLOR_FORMATTING_PATTERN, "", text))
+def create_link(text: str, url: str) -> str:
+    return "\033]8;;{url}\033\\{text}\033]8;;\033\\".format(url=url, text=text)
+
+
+def real_len(text: str) -> int:
+    # ignore colors if existing
+    result = re.sub(COLOR_FORMATTING_PATTERN, "", text)
+    # Ignore link control characters and metadata
+    result = re.sub(LINK_START_PATTERN, "", result)
+    result = result.replace(LINK_END, "")
+
+    return len(result)
 
 
 def _get_default_length():
@@ -78,21 +90,25 @@ def process_formatter_config(text: str) -> str:
             output = output.replace(char, alternative)
         output = output.encode("ascii", "ignore").decode()
 
+    if not sys.stdout.isatty():
+        output = re.sub(LINK_START_PATTERN, "", output)
+        output = output.replace(LINK_END, "")
+
     return output
 
 
-# We can't rely on textwrap because of the len_no_color function
+# We can't rely on textwrap because of the real_len function
 # Textwrap is using a magic regex instead
 def wrap_text(text: str, max_width: int) -> List[str]:
-    if len_no_color(text) <= max_width:
+    if real_len(text) <= max_width:
         return [text]
 
     words = text.split()
     wrapped_lines = []
     current_line = ""
 
     for word in words:
-        if len_no_color(current_line) + len_no_color(word) >= max_width:
+        if real_len(current_line) + real_len(word) >= max_width:
             wrapped_lines.append(current_line.strip())
             current_line = word
         else:
@@ -140,14 +156,14 @@ def __init__(
 
     @staticmethod
     def ljust(string: str, total_length: int) -> str:
-        str_length = len_no_color(string)
+        str_length = real_len(string)
         if str_length >= total_length:
             return string
         return string + " " * (total_length - str_length)
 
     @staticmethod
     def rjust(string: str, total_length: int) -> str:
-        str_length = len_no_color(string)
+        str_length = real_len(string)
         if str_length >= total_length:
             return string
         return " " * (total_length - str_length) + string
@@ -179,7 +195,7 @@ def _get_column_sizes(self) -> List[int]:
         column_sizes = []
         for i in range(len(all_content[0])):
             column_sizes.append(
-                max(len_no_color(str(item[i])) for item in all_content)
+                max(real_len(str(item[i])) for item in all_content)
             )
 
         return column_sizes

uaclient/cli/tests/test_cli_formatter.py

@@ -8,7 +8,8 @@
 from uaclient.cli.formatter import (
     SuggestionBlock,
     Table,
-    len_no_color,
+    create_link,
+    real_len,
     wrap_text,
 )
 
@@ -74,7 +75,15 @@ def test_suggestions_config(self, config_value, FakeConfig):
         assert POFC.show_suggestions is False
 
 
-class TestLenNoColor:
+class TestCreateLink:
+    def test_creates_link(self):
+        assert (
+            "\x1b]8;;http://example.test\x1b\\some link\x1b]8;;\x1b\\"
+            == create_link(text="some link", url="http://example.test")
+        )
+
+
+class TestRealLen:
     @pytest.mark.parametrize(
         "input_string,expected_length",
         (
@@ -87,7 +96,15 @@ class TestLenNoColor:
         ),
     )
     def test_length_ignores_color(self, input_string, expected_length):
-        assert expected_length == len_no_color(input_string)
+        assert expected_length == real_len(input_string)
+
+    def test_length_ignores_links(self):
+        str_with_link = (
+            "There is an "
+            "\x1b]8;;https://example.com\x1b\\example link here\x1b]8;;\x1b\\"
+            " to be clicked"
+        )
+        assert 43 == real_len(str_with_link)
 
 
 class TestWrapText:
@@ -119,6 +136,19 @@ def test_single_line_wrapped(self):
             "too",
         ] == wrap_text(colored_string, 20)
 
+        string_with_link = (
+            "There is an "
+            "\x1b]8;;https://example.com\x1b\\example link here\x1b]8;;\x1b\\"
+            " to be clicked"
+        )
+        assert len(string_with_link) == 76
+        assert [string_with_link] == wrap_text(string_with_link, 45)
+        assert [
+            "There is an \x1b]8;;https://example.com\x1b\\example",
+            "link here\x1b]8;;\x1b\\ to be",
+            "clicked",
+        ] == wrap_text(string_with_link, 20)
+
 
 class TestTable:
     @pytest.mark.parametrize(
@@ -290,15 +320,15 @@ def test_to_string_wraps_to_terminal_size(
         table = Table(
             ["header1", "h2", "h3", "h4"],
             [
-                ["a", "bc", "de", "f"],
+                [create_link(text="a", url="example.com"), "bc", "de", "f"],
                 ["b", "de", "fg", "wow this is a really big string of data"],
                 ["c", "fg", "hijkl", "m"],
             ],
         )
         assert table.to_string() == textwrap.dedent(
             """\
             \x1b[1mheader1  h2  h3     h4\x1b[0m
-            a        bc  de     f
+            \x1b]8;;example.com\x1b\\a\x1b]8;;\x1b\\        bc  de     f
             b        de  fg     wow this is a
                                 really big string of
                                 data
@@ -319,7 +349,7 @@ def test_to_string_no_wrap_if_no_tty(
         table = Table(
             ["header1", "h2", "h3", "h4"],
             [
-                ["a", "bc", "de", "f"],
+                [create_link(text="a", url="example.com"), "bc", "de", "f"],
                 [
                     "b",
                     "de",