An empty api_root now fails at start, for an enabled find_a_tender or fts_mock source and for fetch once

An enabled Find a Tender or mock source with no api_root used to start
and then fail on every fetch. Its worker now returns an error naming the
missing key before it starts, which stops Run. "fetch once" checks
sources.find_a_tender.api_root the same way. TestRunMissingAPIRoot covers
both sources, and TestRunLogsSourceErrors sets an api_root so it still
tests the zero interval. The section docs and internal/config/README.md
say what an empty api_root means.

internal/cli/fetch/once.go

@@ -2,6 +2,7 @@ package fetch
 
 import (
 	"encoding/json"
+	"errors"
 	"fmt"
 	"log/slog"
 	"slices"
@@ -73,6 +74,9 @@ func commandOnce(opts *cli.Options) *cobra.Command {
 				return sinceErr
 			}
 
+			if conf.Sources.FindATender.APIRoot == "" {
+				return errors.New("sources.find_a_tender.api_root is not set")
+			}
 			findATender := findatender.New(conf, conf.Sources.FindATender.APIRoot)
 			defer findATender.Shutdown()
 

internal/config/README.md

@@ -37,8 +37,8 @@ is kept.
 | `database.file` | string | | Path to the SQLite database file, used by the `migrate` commands. Empty: commands that need the database fail |
 | `sources.<source>.enabled` | bool | `false` | For every source |
 | `sources.<source>.interval` | duration | `10m` | For every source; e.g. `30s`, `1h`. Must be greater than 0; turn a source off with `enabled` |
-| `sources.find_a_tender.api_root` | string | `https://www.find-tender.service.gov.uk/api/1.0` | URL of the Find a Tender API |
-| `sources.fts_mock.api_root` | string | | URL of the mock FTS server (see `internal/mock`); must be set when the source is enabled |
+| `sources.find_a_tender.api_root` | string | `https://www.find-tender.service.gov.uk/api/1.0` | URL of the Find a Tender API. Empty: the source fails to start if enabled, and `fetch once` fails |
+| `sources.fts_mock.api_root` | string | | URL of the mock FTS server (see `internal/mock`). Empty: the source fails to start if enabled |
 | `sources.sleeper.block_shutdown` | bool | `false` | Test source: if true, its sleep ignores shutdown |
 | `server.host` | string | `127.0.0.1` | Address to listen on; empty: every interface |
 | `server.port` | int | `9393` | Port to listen on; `0`: any free port |

internal/config/conf_source_findatender.go

@@ -6,7 +6,8 @@ import "reflect"
 const JSCKSourceFindATender string = "find_a_tender"
 
 // JSCSourceFindATender configures fetching from the Find a Tender
-// OCDS API at APIRoot.
+// OCDS API at APIRoot. Empty: the source fails to start if it is enabled,
+// and `fetch once` fails.
 type JSCSourceFindATender struct {
 	JSCSourcesSource
 	APIRoot string `cfg:"api_root" default:"https://www.find-tender.service.gov.uk/api/1.0"`

internal/config/conf_source_ftsmock.go

@@ -6,8 +6,8 @@ import "reflect"
 const JSCKSourceFTSMock string = "fts_mock"
 
 // JSCSourceFTSMock configures fetching from a Find a Tender mock
-// server (cmd/mock-fts) at APIRoot, which has no default and must be set when
-// the source is enabled.
+// server (cmd/mock-fts) at APIRoot, which has no default. Empty: the source
+// fails to start if it is enabled.
 type JSCSourceFTSMock struct {
 	JSCSourcesSource
 	APIRoot string `cfg:"api_root"`

internal/fetcher/fetcher_test.go

@@ -229,7 +229,9 @@ func TestRunLogsSourceErrors(t *testing.T) {
 	// A zero interval makes each worker fail straight away.
 	conf := &config.JobSearchConfig{}
 	conf.Sources.FindATender.Enabled = true
+	conf.Sources.FindATender.APIRoot = "http://127.0.0.1:1"
 	conf.Sources.FTSMock.Enabled = true
+	conf.Sources.FTSMock.APIRoot = "http://127.0.0.1:1"
 	conf.Sources.Sleeper.Enabled = true
 	err := Run(context.Background(), conf, time.Time{})
 
@@ -248,6 +250,37 @@ func TestRunLogsSourceErrors(t *testing.T) {
 	}
 }
 
+// An enabled Find a Tender or mock source with no api_root fails straight
+// away, naming the setting.
+func TestRunMissingAPIRoot(t *testing.T) {
+	quiet := slog.New(slog.DiscardHandler)
+	tests := []struct {
+		name   string
+		enable func(*config.JobSearchConfig)
+		key    string
+	}{
+		{"find_a_tender", func(conf *config.JobSearchConfig) {
+			conf.Sources.FindATender.Enabled = true
+			conf.Sources.FindATender.Interval = time.Hour
+		}, "sources.find_a_tender.api_root"},
+		{"fts_mock", func(conf *config.JobSearchConfig) {
+			conf.Sources.FTSMock.Enabled = true
+			conf.Sources.FTSMock.Interval = time.Hour
+		}, "sources.fts_mock.api_root"},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			conf := &config.JobSearchConfig{}
+			tt.enable(conf)
+
+			err := Run(context.Background(), conf, time.Time{}, WithLogger(quiet))
+			if err == nil || !strings.Contains(err.Error(), tt.key) {
+				t.Errorf("Run = %v; want an error naming %s", err, tt.key)
+			}
+		})
+	}
+}
+
 func TestRunNoSourcesEnabled(t *testing.T) {
 	done := make(chan struct{})
 	go func() {

internal/fetcher/worker_findatender.go

@@ -20,6 +20,10 @@ func runFindAOpportunity(
 	conf *config.JobSearchConfig,
 	since time.Time,
 ) error {
+	if conf.Sources.FindATender.APIRoot == "" {
+		return errors.New("fetcher: sources.find_a_tender.api_root is not set")
+	}
+
 	worker := util.Worker{
 		Logger:   tagged(logger),
 		Name:     "FindAOpportunity",

internal/fetcher/worker_ftsmock.go

@@ -20,6 +20,10 @@ func runFTSMock(
 	conf *config.JobSearchConfig,
 	since time.Time,
 ) error {
+	if conf.Sources.FTSMock.APIRoot == "" {
+		return errors.New("fetcher: sources.fts_mock.api_root is not set")
+	}
+
 	worker := util.Worker{
 		Logger:   tagged(logger),
 		Name:     "FTSMock",