[log_format] check that patterns have a timestamp capture

src/log_format.cc

@@ -931,12 +931,18 @@ external_log_format::scan(logfile& lf,
             ts = string_fragment::from_bytes(combined_datetime_buf, ts_str_len);
         }
 
-        if ((last = this->lf_date_time.scan(ts->data(),
-                                            ts->length(),
-                                            this->get_timestamp_formats(),
-                                            &log_time_tm,
-                                            log_tv))
-            == nullptr)
+        auto level = this->convert_level(
+            level_cap.value_or(string_fragment::invalid()), &sbc);
+
+        if (!ts) {
+            level = log_level_t::LEVEL_INVALID;
+        } else if ((last
+                    = this->lf_date_time.scan(ts->data(),
+                                              ts->length(),
+                                              this->get_timestamp_formats(),
+                                              &log_time_tm,
+                                              log_tv))
+                   == nullptr)
         {
             this->lf_date_time.unlock();
             if ((last = this->lf_date_time.scan(ts->data(),
@@ -950,9 +956,6 @@ external_log_format::scan(logfile& lf,
             }
         }
 
-        auto level = this->convert_level(
-            level_cap.value_or(string_fragment::invalid()), &sbc);
-
         this->lf_timestamp_flags = log_time_tm.et_flags;
 
         if (!((log_time_tm.et_flags & ETF_DAY_SET)
@@ -2276,6 +2279,16 @@ external_log_format::build(std::vector<lnav::console::user_message>& errors)
             }
         }
 
+        if (!pat.p_module_format && pat.p_timestamp_field_index == -1) {
+            errors.emplace_back(
+                lnav::console::user_message::error(
+                    attr_line_t("invalid pattern: ")
+                        .append_quoted(lnav::roles::symbol(pat.p_config_path)))
+                    .with_reason("no timestamp capture found in the pattern")
+                    .with_snippets(this->get_snippets())
+                    .with_help("all log messages need a timestamp"));
+        }
+
         if (!this->elf_level_field.empty() && pat.p_level_field_index == -1) {
             log_warning("%s:level field '%s' not found in pattern",
                         pat.p_config_path.c_str(),

test/expected/test_format_loader.sh_5992e2695b7e6cf1f3520dbb87af8fc2b8f27088.err

@@ -167,6 +167,10 @@
    reason: pattern does not match any samples
  --> {test_dir}/bad-config/formats/invalid-sample/format.json:7
  =   help: every pattern should have at least one sample that it matches
+✘ error: invalid pattern: “/invalid_props_log/regex/std”
+ reason: no timestamp capture found in the pattern
+ --> {test_dir}/bad-config/formats/invalid-properties/format.json:4
+ = help: all log messages need a timestamp
 ⚠ warning: invalid value “/invalid_props_log/value/non-existent”
    reason: no patterns have a capture named “non-existent”
  --> {test_dir}/bad-config/formats/invalid-properties/format.json:4

test/expected/test_format_loader.sh_fca6c1fb9f3aaa69b3ffb2d1a8a86434b2f4a247.err

@@ -58,6 +58,10 @@
 ✘ error: “foobar_log” is not a valid log format
  reason: log message samples must be included in a format definition
  --> {test_dir}/bad-config-json/formats/invalid-json/format.json:3
+✘ error: invalid pattern: “/invalid_key_log/regex/foo”
+ reason: no timestamp capture found in the pattern
+ --> {test_dir}/bad-config-json/formats/invalid-key/format.json:4
+ = help: all log messages need a timestamp
 ✘ error: “invalid_key_log” is not a valid log format
  reason: structured logs cannot have regexes
  --> {test_dir}/bad-config-json/formats/invalid-key/format.json:4