From 1ce5c840ac64509d937fd510eef3915f7a69d2d6 Mon Sep 17 00:00:00 2001
From: Leo Antunes <leo@costela.net>
Date: Fri, 19 Jan 2024 16:02:29 +0100
Subject: [PATCH] feat: automatically detect imported version

---
 README.md             |  6 ------
 internal/constants.go | 11 -----------
 tracer.go             | 24 ++++++++++++++++++++----
 tracer_test.go        |  2 --
 4 files changed, 20 insertions(+), 23 deletions(-)
 delete mode 100644 internal/constants.go

diff --git a/README.md b/README.md
index 1ab6604..eaa0085 100644
--- a/README.md
+++ b/README.md
@@ -12,12 +12,6 @@ instrumentation for the [jackc/pgx](https://github.com/jackc/pgx) library.
 
 ## Usage
 
-Make sure you have a suitable pgx version:
-
-```bash
-go get github.com/jackc/pgx/v5
-```
-
 Install the library:
 
 ```go
diff --git a/internal/constants.go b/internal/constants.go
deleted file mode 100644
index 3ec7946..0000000
--- a/internal/constants.go
+++ /dev/null
@@ -1,11 +0,0 @@
-package internal
-
-const (
-	// TracerName is the name of the tracer. This will be used as an attribute
-	// on each span.
-	TracerName = "github.com/exaring/otelpgx"
-
-	// InstrumentationVersion is the version of the otelpgx library. This will
-	// be used as an attribute on each span.
-	InstrumentationVersion = "v0.5.2"
-)
diff --git a/tracer.go b/tracer.go
index 361be69..5a6df03 100644
--- a/tracer.go
+++ b/tracer.go
@@ -5,6 +5,7 @@ import (
 	"database/sql"
 	"errors"
 	"fmt"
+	"runtime/debug"
 	"strings"
 
 	"github.com/jackc/pgx/v5"
@@ -14,8 +15,12 @@ import (
 	"go.opentelemetry.io/otel/codes"
 	semconv "go.opentelemetry.io/otel/semconv/v1.17.0"
 	"go.opentelemetry.io/otel/trace"
+)
+
+const (
+	tracerName = "github.com/exaring/otelpgx"
 
-	"github.com/exaring/otelpgx/internal"
+	sqlOperationUnknown = "UNKNOWN"
 )
 
 const (
@@ -70,7 +75,7 @@ func NewTracer(opts ...Option) *Tracer {
 	}
 
 	return &Tracer{
-		tracer:            cfg.tp.Tracer(internal.TracerName, trace.WithInstrumentationVersion(internal.InstrumentationVersion)),
+		tracer:            cfg.tp.Tracer(tracerName, trace.WithInstrumentationVersion(findOwnImportedVersion())),
 		attrs:             cfg.attrs,
 		trimQuerySpanName: cfg.trimQuerySpanName,
 		spanNameFunc:      cfg.spanNameFunc,
@@ -91,8 +96,6 @@ func recordError(span trace.Span, err error) {
 	}
 }
 
-const sqlOperationUnknown = "UNKNOWN"
-
 // sqlOperationName attempts to get the first 'word' from a given SQL query, which usually
 // is the operation name (e.g. 'SELECT').
 func (t *Tracer) sqlOperationName(stmt string) string {
@@ -354,3 +357,16 @@ func makeParamsAttribute(args []any) attribute.KeyValue {
 	}
 	return QueryParametersKey.StringSlice(ss)
 }
+
+func findOwnImportedVersion() string {
+	buildInfo, ok := debug.ReadBuildInfo()
+	if ok {
+		for _, dep := range buildInfo.Deps {
+			if dep.Path == tracerName {
+				return dep.Version
+			}
+		}
+	}
+
+	return "unknown"
+}
diff --git a/tracer_test.go b/tracer_test.go
index 93a0d96..e821a92 100644
--- a/tracer_test.go
+++ b/tracer_test.go
@@ -97,10 +97,8 @@ var defaultSpanNameFunc SpanNameFunc = func(query string) string {
 		switch {
 		case strings.HasPrefix(line, "--"):
 			prefix = "--"
-
 		case strings.HasPrefix(line, "/*"):
 			prefix = "/*"
-
 		case strings.HasPrefix(line, "#"):
 			prefix = "#"
 		default: