feat(management): search users by email in any case (#443)

GET /api/v2/users with q=email:"..." answers like Auth0's user search: the
email matches in any letter case, unlike users-by-email, and the answer has
the include_totals shape the Go SDK asks for by default. Any other query is
refused with 400 rather than answered wrong.

Goodfeed's backend checks whether an address is taken with this search
before it lets a user change their email.

Reviewed-on: #443
Co-authored-by: Peter Svensson <peter@sparetimecoders.com>

Dockerfile

@@ -1,4 +1,4 @@
-FROM golang:1.27@sha256:192b74998e350966280a2cbffbb6c40064754f7ec005096aa64f04d7ece4467e AS build
+FROM golang:1.27@sha256:162be5298a40ed317005c8339c6de4d10d3eef336d66dc8e9259b03ab9d3a6d2 AS build
 
 WORKDIR /build
 ENV CGO_ENABLED=0

cmd/service/service.go

@@ -102,6 +102,7 @@ func main() {
 
 	// Management API endpoints
 	mux.HandleFunc("GET /api/v2/users-by-email", managementHandler.GetUsersByEmail)
+	mux.HandleFunc("GET /api/v2/users", managementHandler.SearchUsers)
 	mux.HandleFunc("POST /api/v2/users", managementHandler.CreateUser)
 	mux.HandleFunc("PATCH /api/v2/users/", managementHandler.UpdateUser)
 	mux.HandleFunc("POST /api/v2/tickets/password-change", managementHandler.PasswordChangeTicket)

go.mod

@@ -5,7 +5,7 @@ go 1.26.0
 require (
 	github.com/alecthomas/kong v1.16.1
 	github.com/google/uuid v1.6.0
-	github.com/lestrrat-go/jwx/v4 v4.4.0
+	github.com/lestrrat-go/jwx/v4 v4.5.0
 	github.com/rs/cors v1.11.1
 )
 
@@ -13,5 +13,5 @@ require (
 	github.com/lestrrat-go/dsig v1.4.0 // indirect
 	github.com/lestrrat-go/option/v3 v3.0.0-alpha1 // indirect
 	github.com/valyala/fastjson v1.6.10 // indirect
-	golang.org/x/crypto v0.55.0 // indirect
+	golang.org/x/crypto v0.56.0 // indirect
 )

go.sum

@@ -10,17 +10,17 @@ github.com/hexops/gotextdiff v1.0.3 h1:gitA9+qJrrTCsiCl7+kh75nPqQt1cx4ZkudSTLoUq
 github.com/hexops/gotextdiff v1.0.3/go.mod h1:pSWU5MAI3yDq+fZBTazCSJysOMbxWL1BSow5/V2vxeg=
 github.com/lestrrat-go/dsig v1.4.0 h1:g7LUjK8cT74A5DzBXJI5HzsJuLhoYN0Wzj4nuOMIrH8=
 github.com/lestrrat-go/dsig v1.4.0/go.mod h1:I8Nddg/vN2cUl/h8N7SRRApLnNNeyZPIqLYpvpOtGGo=
-github.com/lestrrat-go/jwx/v4 v4.4.0 h1:CzoK8+u++WF7vVEmxx9fB8VaheeXWZ698F6HZbrl6SI=
-github.com/lestrrat-go/jwx/v4 v4.4.0/go.mod h1:65utsGK/iSrjgGfu6iqj/TAvSfia6SSXkRpjHcKcTyg=
+github.com/lestrrat-go/jwx/v4 v4.5.0 h1:lgU8YcqaJo/iZllX4AvSaQTzT2XpWWMrDcPMe6+KzqI=
+github.com/lestrrat-go/jwx/v4 v4.5.0/go.mod h1:HpoztFC5HrNj9iKkZJ3XTQQgzCY2Zto/29n89QhTC10=
 github.com/lestrrat-go/option/v3 v3.0.0-alpha1 h1:dvdzLwm/Ba5CJUF3jQP7w/iNYSLfy7yyh9XXNa1WjxI=
 github.com/lestrrat-go/option/v3 v3.0.0-alpha1/go.mod h1:5KSg20dfsKkNJtjDmaQRLZVXuUrzuCCcz/gbDK0pfKk=
 github.com/rs/cors v1.11.1 h1:eU3gRzXLRK57F5rKMGMZURNdIG4EoAmX8k94r9wXWHA=
 github.com/rs/cors v1.11.1/go.mod h1:XyqrcTp5zjWr1wsJ8PIRZssZ8b/WMcMf71DJnit4EMU=
-github.com/stretchr/testify v1.12.0 h1:K6Mr6jO9JICuend/5xzTM03ydSV3vdNRYAdPSukj8uI=
-github.com/stretchr/testify v1.12.0/go.mod h1:bOYBZb5qJ00vPzWfIqBUZPaxK8jWiXc6d3ErP4Ca9Gw=
+github.com/stretchr/testify v1.12.1 h1:EuwCh5fleGS7H32xRwO3wRGT7DxrDhLAT6FF8MpWDWE=
+github.com/stretchr/testify v1.12.1/go.mod h1:MDEgiDPPsNp5cuIrHPPCyornHKgEVbtFUmoNlxoYthg=
 github.com/valyala/fastjson v1.6.10 h1:/yjJg8jaVQdYR3arGxPE2X5z89xrlhS0eGXdv+ADTh4=
 github.com/valyala/fastjson v1.6.10/go.mod h1:e6FubmQouUNP73jtMLmcbxS6ydWIpOfhz34TSfO3JaE=
-golang.org/x/crypto v0.55.0 h1:+KWHjbgOaAQ66dh/YlkZKHlz9ZUlq61AFirAR9ntP8M=
-golang.org/x/crypto v0.55.0/go.mod h1:uq0V9dE/fzQuJtbnL+2EhWOE63vo164FY8xqEnV9xis=
-gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
-gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
+go.yaml.in/yaml/v3 v3.0.5 h1:N6y/pJk8buWs9NY5ERU2HSMfm+IuD/OtfdAnq6kESPw=
+go.yaml.in/yaml/v3 v3.0.5/go.mod h1:HVTZu1O7/Vkt2N+BFy8Zza+lnLsABggaTM2ZpNIGuKg=
+golang.org/x/crypto v0.56.0 h1:GUh5Ii4J5jtcseSMiRqr1jXCNHoxjeV9Fmekc2oLy6Y=
+golang.org/x/crypto v0.56.0/go.mod h1:OMW5y6CY9l38uPLmxU6l6pwcXp1obtLo3e6gT7gQR2I=

handlers/management.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"log/slog"
 	"net/http"
+	"regexp"
 	"strings"
 
 	"git.unbound.se/unboundsoftware/auth0mock/store"
@@ -152,3 +153,45 @@ func (h *ManagementHandler) PasswordChangeTicket(w http.ResponseWriter, r *http.
 		"ticket": "https://some-url",
 	})
 }
+
+// emailQuery matches the one Lucene query this mock answers: an email phrase,
+// email:"...", with \" and \\ escaped inside it.
+var emailQuery = regexp.MustCompile(`^email:"((?:[^"\\]|\\.)*)"$`)
+
+// SearchUsers handles GET /api/v2/users. Like Auth0's user search it matches
+// email in any letter case (users-by-email does not), and it answers in the
+// shape the Go SDK asks for by default (include_totals=true). Only an email
+// phrase is understood; any other query is refused rather than answered wrong.
+func (h *ManagementHandler) SearchUsers(w http.ResponseWriter, r *http.Request) {
+	q := r.URL.Query().Get("q")
+	match := emailQuery.FindStringSubmatch(q)
+	if match == nil {
+		http.Error(w, "only q=email:\"...\" is supported", http.StatusBadRequest)
+		return
+	}
+	email := strings.NewReplacer(`\"`, `"`, `\\`, `\`).Replace(match[1])
+
+	h.logger.Debug("searching users", "email", email)
+
+	users := []UserResponse{}
+	for _, user := range h.userStore.List() {
+		if strings.EqualFold(user.Email, email) {
+			users = append(users, UserResponse{
+				Email:      user.Email,
+				GivenName:  user.GivenName,
+				FamilyName: user.FamilyName,
+				UserID:     fmt.Sprintf("auth0|%s", user.UserID),
+				Picture:    user.Picture,
+			})
+		}
+	}
+
+	w.Header().Set("Content-Type", "application/json")
+	json.NewEncoder(w).Encode(map[string]any{
+		"start":  0,
+		"limit":  len(users),
+		"length": len(users),
+		"total":  len(users),
+		"users":  users,
+	})
+}

handlers/management_test.go

@@ -0,0 +1,66 @@
+package handlers
+
+import (
+	"encoding/json"
+	"log/slog"
+	"net/http"
+	"net/http/httptest"
+	"net/url"
+	"testing"
+
+	"git.unbound.se/unboundsoftware/auth0mock/store"
+)
+
+func searchUsers(t *testing.T, h *ManagementHandler, q string) (int, []UserResponse) {
+	t.Helper()
+	req := httptest.NewRequest(http.MethodGet, "/api/v2/users?search_engine=v3&include_totals=true&q="+url.QueryEscape(q), nil)
+	rec := httptest.NewRecorder()
+	h.SearchUsers(rec, req)
+	if rec.Code != http.StatusOK {
+		return rec.Code, nil
+	}
+	var body struct {
+		Total int            `json:"total"`
+		Users []UserResponse `json:"users"`
+	}
+	if err := json.NewDecoder(rec.Body).Decode(&body); err != nil {
+		t.Fatalf("decode: %v", err)
+	}
+	if body.Total != len(body.Users) {
+		t.Fatalf("total %d, users %d", body.Total, len(body.Users))
+	}
+	return rec.Code, body.Users
+}
+
+// The search matches email in any letter case, as Auth0's does: a backend that
+// checks whether an address is taken must find it however it was typed.
+func TestSearchUsersMatchesEmailInAnyCase(t *testing.T) {
+	users := store.NewUserStore()
+	users.Create("anna@kpmg.se", &store.User{GivenName: "Anna"})
+	users.Create("bob@acme.se", &store.User{GivenName: "Bob"})
+	h := NewManagementHandler(users, slog.New(slog.DiscardHandler))
+
+	for _, q := range []string{`email:"anna@kpmg.se"`, `email:"ANNA@KPMG.SE"`, `email:"Anna@Kpmg.se"`} {
+		code, found := searchUsers(t, h, q)
+		if code != http.StatusOK || len(found) != 1 || found[0].UserID != "auth0|anna@kpmg.se" {
+			t.Fatalf("%s: code %d, found %+v", q, code, found)
+		}
+	}
+
+	if _, found := searchUsers(t, h, `email:"nobody@acme.se"`); len(found) != 0 {
+		t.Fatalf("an unknown address found %+v", found)
+	}
+	// A quoted * is part of the address, not a wildcard.
+	if _, found := searchUsers(t, h, `email:"*@kpmg.se"`); len(found) != 0 {
+		t.Fatalf("a quoted * matched %+v", found)
+	}
+}
+
+func TestSearchUsersRefusesOtherQueries(t *testing.T) {
+	h := NewManagementHandler(store.NewUserStore(), slog.New(slog.DiscardHandler))
+	for _, q := range []string{"", "name:anna", `email:"a@b.se" OR name:x`} {
+		if code, _ := searchUsers(t, h, q); code != http.StatusBadRequest {
+			t.Fatalf("%q: code %d, want 400", q, code)
+		}
+	}
+}