From 93cc6411ea9649957be37fdb20194d0b49839fc5 Mon Sep 17 00:00:00 2001
From: Frank Viernau <frank_viernau@epam.com>
Date: Tue, 14 Feb 2023 15:19:04 +0100
Subject: [PATCH] refactor(GoMod): Use option `-json` with `go list` to get
 module names

The `-json` option allows specifying a comma separated list of
property names to include in the output. The `go list` command has a
mechanism for skipping certain processing steps which are not needed for
computing the values corresponding to those specified property names,
see [^1] and [^2]. Such a mechanism is not in place for the `-f` option.

Migrate from `-f` to `-json` to benefit from above mechanism, removing
potential sources of issues. It could be that this allows to drop the
parameter `-buildvcs=false`, which is left for future investigation.

The primary reason for switching to `-json` is to extend the mentioned
mechanism in `go list` to conditionally skip computing embed files in
an analog way which would fix [^4].

[^1]: https://github.com/golang/go/blob/0cd309e12818f988693bf8e4d9f1453331dcf9f2/src/cmd/go/internal/load/pkg.go#L2768-L2776
[^2]: https://github.com/golang/go/blob/0cd309e12818f988693bf8e4d9f1453331dcf9f2/src/cmd/go/internal/list/list.go#L605-L606
[^3]: https://github.com/golang/go/issues/49534#issuecomment-1184587164
[^4]: https://github.com/oss-review-toolkit/ort/issues/5560

Signed-off-by: Frank Viernau <frank_viernau@epam.com>
---
 analyzer/src/main/kotlin/managers/GoMod.kt | 21 +++++++++++++++++----
 1 file changed, 17 insertions(+), 4 deletions(-)

diff --git a/analyzer/src/main/kotlin/managers/GoMod.kt b/analyzer/src/main/kotlin/managers/GoMod.kt
index 50bb8b785eda7..72c39d6c61206 100644
--- a/analyzer/src/main/kotlin/managers/GoMod.kt
+++ b/analyzer/src/main/kotlin/managers/GoMod.kt
@@ -288,13 +288,26 @@ class GoMod(
 
         // See https://pkg.go.dev/text/template for the format syntax.
         val list = run(
-            "list", "-deps", "-f", "{{with .Module}}{{.Path}} {{.Version}}{{end}}", "-buildvcs=false", "./...",
+            "list", "-deps", "-json=Module", "-buildvcs=false", "./...",
             workingDir = projectDir
         )
 
-        list.stdout.lines().forEach { line ->
-            val columns = line.splitOnWhitespace()
-            if (columns.size in 1..2) result += columns.first()
+        data class DepInfo(
+            @JsonProperty("Module")
+            val module: ModuleInfo? = null
+        )
+
+        list.stdout.byteInputStream().use { inputStream ->
+            JsonFactory().createParser(inputStream).apply {
+                codec = ObjectMapper()
+                nextToken()
+
+                while (hasCurrentToken()) {
+                    val moduleInfo =  jsonMapper.readValue(this, DepInfo::class.java).module
+                    if (moduleInfo != null) result += moduleInfo.path
+                    nextToken()
+                }
+            }
         }
 
         return result