Add verbose_errors config and special command (#1455)

* Add verbose_errors config

* Update changelog

* Add special command

* Blackify

changelog.rst

@@ -4,7 +4,9 @@ Upcoming
 Features:
 ---------
 * Support `PGAPPNAME` as an environment variable and `--application-name` as a command line argument.
-* Show Postgres notifications
+* Add `verbose_errors` config and `\v` special command which enable the
+  displaying of all Postgres error fields received.
+* Show Postgres notifications.
 
 Bug fixes:
 ----------

pgcli/main.py

@@ -75,6 +75,7 @@
 
 from psycopg import OperationalError, InterfaceError, Notify
 from psycopg.conninfo import make_conninfo, conninfo_to_dict
+from psycopg.errors import Diagnostic
 
 from collections import namedtuple
 
@@ -248,6 +249,9 @@ def __init__(
         )
 
         self.less_chatty = bool(less_chatty) or c["main"].as_bool("less_chatty")
+        self.verbose_errors = "verbose_errors" in c["main"] and c["main"].as_bool(
+            "verbose_errors"
+        )
         self.null_string = c["main"].get("null_string", "<null>")
         self.prompt_format = (
             prompt
@@ -389,6 +393,26 @@ def register_special_commands(self):
             "Echo a string to the query output channel.",
         )
 
+        self.pgspecial.register(
+            self.toggle_verbose_errors,
+            "\\v",
+            "\\v [on|off]",
+            "Toggle verbose errors.",
+        )
+
+    def toggle_verbose_errors(self, pattern, **_):
+        flag = pattern.strip()
+
+        if flag == "on":
+            self.verbose_errors = True
+        elif flag == "off":
+            self.verbose_errors = False
+        else:
+            self.verbose_errors = not self.verbose_errors
+
+        message = "Verbose errors " + "on." if self.verbose_errors else "off."
+        return [(None, None, None, message)]
+
     def echo(self, pattern, **_):
         return [(None, None, None, pattern)]
 
@@ -1080,7 +1104,7 @@ def _evaluate_command(self, text):
         res = self.pgexecute.run(
             text,
             self.pgspecial,
-            exception_formatter,
+            lambda x: exception_formatter(x, self.verbose_errors),
             on_error_resume,
             explain_mode=self.explain_mode,
         )
@@ -1618,8 +1642,71 @@ def is_select(status):
     return status.split(None, 1)[0].lower() == "select"
 
 
-def exception_formatter(e):
-    return click.style(str(e), fg="red")
+def diagnostic_output(diagnostic: Diagnostic) -> str:
+    fields = []
+
+    if diagnostic.severity is not None:
+        fields.append("Severity: " + diagnostic.severity)
+
+    if diagnostic.severity_nonlocalized is not None:
+        fields.append("Severity (non-localized): " + diagnostic.severity_nonlocalized)
+
+    if diagnostic.sqlstate is not None:
+        fields.append("SQLSTATE code: " + diagnostic.sqlstate)
+
+    if diagnostic.message_primary is not None:
+        fields.append("Message: " + diagnostic.message_primary)
+
+    if diagnostic.message_detail is not None:
+        fields.append("Detail: " + diagnostic.message_detail)
+
+    if diagnostic.message_hint is not None:
+        fields.append("Hint: " + diagnostic.message_hint)
+
+    if diagnostic.statement_position is not None:
+        fields.append("Position: " + diagnostic.statement_position)
+
+    if diagnostic.internal_position is not None:
+        fields.append("Internal position: " + diagnostic.internal_position)
+
+    if diagnostic.internal_query is not None:
+        fields.append("Internal query: " + diagnostic.internal_query)
+
+    if diagnostic.context is not None:
+        fields.append("Where: " + diagnostic.context)
+
+    if diagnostic.schema_name is not None:
+        fields.append("Schema name: " + diagnostic.schema_name)
+
+    if diagnostic.table_name is not None:
+        fields.append("Table name: " + diagnostic.table_name)
+
+    if diagnostic.column_name is not None:
+        fields.append("Column name: " + diagnostic.column_name)
+
+    if diagnostic.datatype_name is not None:
+        fields.append("Data type name: " + diagnostic.datatype_name)
+
+    if diagnostic.constraint_name is not None:
+        fields.append("Constraint name: " + diagnostic.constraint_name)
+
+    if diagnostic.source_file is not None:
+        fields.append("File: " + diagnostic.source_file)
+
+    if diagnostic.source_line is not None:
+        fields.append("Line: " + diagnostic.source_line)
+
+    if diagnostic.source_function is not None:
+        fields.append("Routine: " + diagnostic.source_function)
+
+    return "\n".join(fields)
+
+
+def exception_formatter(e, verbose_errors: bool = False):
+    s = str(e)
+    if verbose_errors:
+        s += "\n" + diagnostic_output(e.diag)
+    return click.style(s, fg="red")
 
 
 def format_output(title, cur, headers, status, settings, explain_mode=False):

pgcli/pgclirc

@@ -156,6 +156,11 @@ max_field_width = 500
 # Skip intro on startup and goodbye on exit
 less_chatty = False
 
+# Show all Postgres error fields (as listed in
+# https://www.postgresql.org/docs/current/protocol-error-fields.html).
+# Can be toggled with \v.
+verbose_errors = False
+
 # Postgres prompt
 # \t - Current date and time
 # \u - Username

tests/test_main.py

@@ -299,6 +299,24 @@ def test_i_works(tmpdir, executor):
     run(executor, statement, pgspecial=cli.pgspecial)
 
 
+@dbtest
+def test_toggle_verbose_errors(executor):
+    cli = PGCli(pgexecute=executor)
+
+    cli._evaluate_command("\\v on")
+    assert cli.verbose_errors
+    output, _ = cli._evaluate_command("SELECT 1/0")
+    assert "SQLSTATE" in output[0]
+
+    cli._evaluate_command("\\v off")
+    assert not cli.verbose_errors
+    output, _ = cli._evaluate_command("SELECT 1/0")
+    assert "SQLSTATE" not in output[0]
+
+    cli._evaluate_command("\\v")
+    assert cli.verbose_errors
+
+
 @dbtest
 def test_echo_works(executor):
     cli = PGCli(pgexecute=executor)

tests/test_pgexecute.py

@@ -1,3 +1,4 @@
+import re
 from textwrap import dedent
 
 import psycopg
@@ -6,7 +7,7 @@
 from pgspecial.main import PGSpecial, NO_QUERY
 from utils import run, dbtest, requires_json, requires_jsonb
 
-from pgcli.main import PGCli
+from pgcli.main import PGCli, exception_formatter as main_exception_formatter
 from pgcli.packages.parseutils.meta import FunctionMetadata
 
 
@@ -219,8 +220,33 @@ def test_database_list(executor):
 
 @dbtest
 def test_invalid_syntax(executor, exception_formatter):
-    result = run(executor, "invalid syntax!", exception_formatter=exception_formatter)
+    result = run(
+        executor,
+        "invalid syntax!",
+        exception_formatter=lambda x: main_exception_formatter(x, verbose_errors=False),
+    )
     assert 'syntax error at or near "invalid"' in result[0]
+    assert "SQLSTATE" not in result[0]
+
+
+@dbtest
+def test_invalid_syntax_verbose(executor):
+    result = run(
+        executor,
+        "invalid syntax!",
+        exception_formatter=lambda x: main_exception_formatter(x, verbose_errors=True),
+    )
+    fields = r"""
+Severity: ERROR
+Severity \(non-localized\): ERROR
+SQLSTATE code: 42601
+Message: syntax error at or near "invalid"
+Position: 1
+File: scan\.l
+Line: \d+
+Routine: scanner_yyerror
+    """.strip()
+    assert re.search(fields, result[0])
 
 
 @dbtest