Fix repetitive diagnosis output in init response (#1890)

Signed-off-by: buraksenn <buraksenb@gmail.com>

internal/command/init.go

@@ -292,8 +292,7 @@ func (c *InitCommand) Run(args []string) int {
 
 	// Now, we can check the diagnostics from the early configuration and the
 	// backend.
-	diags = diags.Append(earlyConfDiags)
-	diags = diags.Append(backDiags)
+	diags = diags.Append(earlyConfDiags.StrictDeduplicateMerge(backDiags))
 	if earlyConfDiags.HasErrors() {
 		c.Ui.Error(strings.TrimSpace(errInitConfigError))
 		c.showDiagnostics(diags)

internal/command/init_test.go

@@ -2995,6 +2995,33 @@ func TestInit_moduleVersion(t *testing.T) {
 	})
 }
 
+func TestInit_invalidExtraLabel(t *testing.T) {
+	td := t.TempDir()
+	testCopyDir(t, testFixturePath("init-syntax-invalid-extra-label"), td)
+	defer testChdir(t, td)()
+
+	ui := cli.NewMockUi()
+	view, _ := testView(t)
+	m := Meta{
+		Ui:   ui,
+		View: view,
+	}
+
+	c := &InitCommand{
+		Meta: m,
+	}
+
+	if code := c.Run(nil); code == 0 {
+		t.Fatalf("succeeded, but was expecting error\nstdout:\n%s\nstderr:\n%s", ui.OutputWriter, ui.ErrorWriter)
+	}
+
+	errStr := ui.ErrorWriter.String()
+	splitted := strings.Split(errStr, "Error: Unsupported block type")
+	if len(splitted) != 2 {
+		t.Fatalf("want exactly one unsupported block type errors but got: %d\nstderr:\n%s\n\nstdout:\n%s", len(splitted)-1, errStr, ui.OutputWriter.String())
+	}
+}
+
 // newMockProviderSource is a helper to succinctly construct a mock provider
 // source that contains a set of packages matching the given provider versions
 // that are available for installation (from temporary local files).

internal/command/testdata/init-syntax-invalid-extra-label/main.tf

@@ -0,0 +1,10 @@
+terraform {
+  extra_label{
+    required_providers {
+      azurerm = {
+        source  = "hashicorp/azurerm"
+        version = "~> 3.0.2"
+      }
+    }
+  }
+}

internal/tfdiags/diagnostic.go

@@ -58,11 +58,19 @@ type Description struct {
 	Detail  string
 }
 
+func (d Description) Equal(other Description) bool {
+	return d.Address == other.Address && d.Summary == other.Summary && d.Detail == other.Detail
+}
+
 type Source struct {
 	Subject *SourceRange
 	Context *SourceRange
 }
 
+func (s Source) Equal(other Source) bool {
+	return s.Subject.Equal(other.Subject) && s.Context.Equal(other.Context)
+}
+
 type FromExpr struct {
 	Expression  hcl.Expression
 	EvalContext *hcl.EvalContext

internal/tfdiags/diagnostics.go

@@ -101,6 +101,23 @@ func (diags Diagnostics) Append(new ...interface{}) Diagnostics {
 	return diags
 }
 
+func (diags Diagnostics) StrictDeduplicateMerge(other Diagnostics) Diagnostics {
+	if len(diags) == 0 {
+		return other
+	}
+
+	for _, d := range diags {
+		for _, o := range other {
+			isEqual := d.Description().Equal(o.Description()) && d.Severity() == o.Severity() && d.Source().Equal(o.Source())
+			if DoNotConsolidateDiagnostic(d) || DoNotConsolidateDiagnostic(o) || !isEqual {
+				diags = append(diags, o)
+			}
+		}
+	}
+
+	return diags
+}
+
 // HasErrors returns true if any of the diagnostics in the list have
 // a severity of Error.
 func (diags Diagnostics) HasErrors() bool {

internal/tfdiags/source_range.go

@@ -16,10 +16,22 @@ type SourceRange struct {
 	Start, End SourcePos
 }
 
+func (r *SourceRange) Equal(other *SourceRange) bool {
+	if r == nil || other == nil {
+		return r == other
+	}
+
+	return r.Filename == other.Filename && r.Start.Equal(other.Start) && r.End.Equal(other.End)
+}
+
 type SourcePos struct {
 	Line, Column, Byte int
 }
 
+func (p SourcePos) Equal(other SourcePos) bool {
+	return p.Line == other.Line && p.Column == other.Column && p.Byte == other.Byte
+}
+
 // StartString returns a string representation of the start of the range,
 // including the filename and the line and column numbers.
 func (r SourceRange) StartString() string {