snapshot of https://github.com/excalidraw/excalidraw.git (master, 2026-09-16; blobs > 131072B omitted)

packages/excalidraw/components/TTDDialog/utils/mermaidError.test.ts

@@ -0,0 +1,155 @@
+import { describe, expect, it } from "vitest";
+
+import {
+  formatMermaidParseErrorMessage,
+  getMermaidErrorLineNumber,
+  getMermaidInactiveParticipant,
+  getMermaidSyntaxErrorGuidance,
+  isMermaidAutoFixableError,
+  isMermaidParseSyntaxError,
+  isMermaidCaretLine,
+} from "./mermaidError";
+
+describe("formatMermaidParseErrorMessage", () => {
+  it("strips the noisy Expecting clause from Mermaid parse errors", () => {
+    const message = `Parse error on line 6:
+... Control Protocol)"]x          L3_UDP
+----------------------^
+Expecting 'SEMI', 'NEWLINE', 'SPACE', got 'NODE_STRING'`;
+
+    expect(formatMermaidParseErrorMessage(message)).toBe(`Parse error on line 6:
+... Control Protocol)"]x          L3_UDP
+----------------------^`);
+  });
+
+  it("keeps Mermaid parse errors unchanged when no Expecting clause exists", () => {
+    const message = `Parse error on line 3:
+... some snippet
+----^`;
+
+    expect(formatMermaidParseErrorMessage(message)).toBe(message);
+  });
+
+  it("does not modify non-Mermaid parse messages", () => {
+    const message =
+      "Unexpected token while parsing JSON. Expecting value at position 10.";
+
+    expect(formatMermaidParseErrorMessage(message)).toBe(message);
+  });
+});
+
+describe("isMermaidCaretLine", () => {
+  it("returns true for Mermaid caret lines", () => {
+    expect(isMermaidCaretLine("-----------------------^")).toBe(true);
+  });
+
+  it("returns false for regular lines", () => {
+    expect(isMermaidCaretLine(`... Control Protocol)"]x`)).toBe(false);
+  });
+});
+
+describe("isMermaidParseSyntaxError", () => {
+  it("returns true for Mermaid parser syntax errors", () => {
+    expect(isMermaidParseSyntaxError("Parse error on line 6: ...")).toBe(true);
+  });
+
+  it("returns true for Mermaid lexical syntax errors", () => {
+    expect(
+      isMermaidParseSyntaxError("Lexical error on line 2. Unrecognized text."),
+    ).toBe(true);
+  });
+
+  it("returns false for non-parse errors", () => {
+    expect(isMermaidParseSyntaxError("Network error")).toBe(false);
+  });
+});
+
+describe("isMermaidAutoFixableError", () => {
+  it("returns true for Mermaid parser syntax errors", () => {
+    expect(isMermaidAutoFixableError("Parse error on line 6: ...")).toBe(true);
+  });
+
+  it("returns true for inactive participant runtime errors", () => {
+    expect(
+      isMermaidAutoFixableError(
+        "Trying to inactivate an inactive participant (QA)",
+      ),
+    ).toBe(true);
+  });
+
+  it("returns false for non-fixable errors", () => {
+    expect(isMermaidAutoFixableError("Network error")).toBe(false);
+  });
+});
+
+describe("getMermaidInactiveParticipant", () => {
+  it("extracts the participant id from inactive participant errors", () => {
+    expect(
+      getMermaidInactiveParticipant(
+        "Trying to inactivate an inactive participant (QA)",
+      ),
+    ).toBe("QA");
+  });
+
+  it("returns null for unrelated errors", () => {
+    expect(
+      getMermaidInactiveParticipant("Parse error on line 3: ..."),
+    ).toBeNull();
+  });
+});
+
+describe("getMermaidErrorLineNumber", () => {
+  it("extracts line number from parse error format", () => {
+    expect(getMermaidErrorLineNumber("Parse error on line 6: ...")).toBe(6);
+  });
+
+  it("extracts line number from lexical error format", () => {
+    expect(
+      getMermaidErrorLineNumber("Lexical error on line 2. Unrecognized text."),
+    ).toBe(2);
+  });
+
+  it("returns null for messages without Mermaid line details", () => {
+    expect(getMermaidErrorLineNumber("Network error")).toBeNull();
+  });
+
+  it("infers line from inactive participant errors when source text is provided", () => {
+    const sourceText = `sequenceDiagram
+  participant QA
+  deactivate QA
+  QA->>QA: Verifies Fix
+  deactivate QA`;
+
+    expect(
+      getMermaidErrorLineNumber(
+        "Trying to inactivate an inactive participant (QA)",
+        sourceText,
+      ),
+    ).toBe(5);
+  });
+});
+
+describe("getMermaidSyntaxErrorGuidance", () => {
+  it("returns summary and likely causes for Mermaid parse errors", () => {
+    const message = `Parse error on line 6:
+... Control Protocol)"]x
+----------------------^`;
+
+    const source = `graph TD
+subgraph Layers["X"]
+  L3_TCP["TCP (Transmission Control Protocol)"]x`;
+
+    expect(getMermaidSyntaxErrorGuidance(message, source)).toEqual({
+      summary: "Syntax error near line 6.",
+      likelyCauses: expect.arrayContaining([
+        "A block is missing an `end` statement.",
+      ]),
+    });
+  });
+
+  it("returns null for non-parse errors", () => {
+    expect(
+      getMermaidSyntaxErrorGuidance("Network error", "graph TD"),
+    ).toBeNull();
+  });
+});